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2714 | cejka | 1 | /* $NetBSD: eval.c,v 1.56 2000/05/22 10:18:46 elric Exp $ */ |
2 | |||
3 | /*- |
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4 | * Copyright (c) 1993 |
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5 | * The Regents of the University of California. All rights reserved. |
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6 | * |
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7 | * This code is derived from software contributed to Berkeley by |
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8 | * Kenneth Almquist. |
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9 | * |
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10 | * Redistribution and use in source and binary forms, with or without |
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11 | * modification, are permitted provided that the following conditions |
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12 | * are met: |
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13 | * 1. Redistributions of source code must retain the above copyright |
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14 | * notice, this list of conditions and the following disclaimer. |
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15 | * 2. Redistributions in binary form must reproduce the above copyright |
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16 | * notice, this list of conditions and the following disclaimer in the |
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17 | * documentation and/or other materials provided with the distribution. |
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18 | * 3. All advertising materials mentioning features or use of this software |
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19 | * must display the following acknowledgement: |
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20 | * This product includes software developed by the University of |
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21 | * California, Berkeley and its contributors. |
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22 | * 4. Neither the name of the University nor the names of its contributors |
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23 | * may be used to endorse or promote products derived from this software |
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24 | * without specific prior written permission. |
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25 | * |
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26 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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27 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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28 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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29 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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30 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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31 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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32 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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33 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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34 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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35 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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36 | * SUCH DAMAGE. |
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37 | */ |
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38 | |||
39 | #include <sys/cdefs.h> |
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40 | #ifndef lint |
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41 | #if 0 |
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42 | static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95"; |
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43 | #else |
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44 | __RCSID("$NetBSD: eval.c,v 1.56 2000/05/22 10:18:46 elric Exp $"); |
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45 | #endif |
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46 | #endif /* not lint */ |
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47 | |||
48 | #include <sys/types.h> |
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49 | #include <signal.h> |
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50 | #include <malloc.h> |
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51 | #include <unistd.h> |
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52 | |||
53 | /* |
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54 | * Evaluate a command. |
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55 | */ |
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56 | |||
57 | #include "shell.h" |
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58 | #include "nodes.h" |
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59 | #include "syntax.h" |
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60 | #include "expand.h" |
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61 | #include "parser.h" |
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62 | #include "jobs.h" |
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63 | #include "eval.h" |
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64 | #include "builtins.h" |
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65 | #include "options.h" |
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66 | #include "exec.h" |
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67 | #include "redir.h" |
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68 | #include "input.h" |
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69 | #include "output.h" |
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70 | #include "trap.h" |
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71 | #include "var.h" |
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72 | #include "memalloc.h" |
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73 | #include "error.h" |
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74 | #include "show.h" |
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75 | #include "mystring.h" |
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76 | #ifndef SMALL |
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77 | #include "myhistedit.h" |
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78 | #endif |
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79 | |||
80 | |||
81 | /* flags in argument to evaltree */ |
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82 | #define EV_EXIT 01 /* exit after evaluating tree */ |
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83 | #define EV_TESTED 02 /* exit status is checked; ignore -e flag */ |
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84 | #define EV_BACKCMD 04 /* command executing within back quotes */ |
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85 | |||
86 | MKINIT int evalskip; /* set if we are skipping commands */ |
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87 | STATIC int skipcount; /* number of levels to skip */ |
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88 | MKINIT int loopnest; /* current loop nesting level */ |
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89 | int funcnest; /* depth of function calls */ |
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90 | |||
91 | |||
92 | char *commandname; |
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93 | struct strlist *cmdenviron; |
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94 | int exitstatus; /* exit status of last command */ |
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95 | int oexitstatus; /* saved exit status */ |
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96 | |||
97 | |||
98 | STATIC void evalloop (union node *, int); |
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99 | STATIC void evalfor (union node *, int); |
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100 | STATIC void evalcase (union node *, int); |
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101 | STATIC void evalsubshell (union node *, int); |
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102 | STATIC void expredir (union node *); |
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103 | STATIC void evalpipe (union node *); |
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104 | STATIC void evalcommand (union node *, int, struct backcmd *); |
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105 | STATIC void prehash (union node *); |
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106 | STATIC int is_assignment_builtin (const char *); |
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107 | STATIC const char *get_standard_path (void); |
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108 | |||
109 | |||
110 | /* |
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111 | * Called to reset things after an exception. |
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112 | */ |
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113 | |||
114 | #ifdef mkinit |
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115 | INCLUDE "eval.h" |
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116 | |||
117 | RESET { |
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118 | evalskip = 0; |
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119 | loopnest = 0; |
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120 | funcnest = 0; |
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121 | } |
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122 | |||
123 | SHELLPROC { |
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124 | exitstatus = 0; |
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125 | } |
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126 | #endif |
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127 | |||
128 | |||
129 | |||
130 | /* |
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131 | * The eval commmand. |
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132 | */ |
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133 | |||
134 | int |
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135 | evalcmd(argc, argv) |
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136 | int argc; |
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137 | char **argv; |
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138 | { |
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139 | char *p; |
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140 | char *concat; |
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141 | char **ap; |
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142 | |||
143 | if (argc > 1) { |
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144 | p = argv[1]; |
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145 | if (argc > 2) { |
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146 | STARTSTACKSTR(concat); |
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147 | ap = argv + 2; |
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148 | for (;;) { |
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149 | while (*p) |
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150 | STPUTC(*p++, concat); |
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151 | if ((p = *ap++) == NULL) |
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152 | break; |
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153 | STPUTC(' ', concat); |
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154 | } |
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155 | STPUTC('\0', concat); |
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156 | p = grabstackstr(concat); |
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157 | } |
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158 | evalstring(p, EV_TESTED); |
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159 | } |
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160 | return exitstatus; |
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161 | } |
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162 | |||
163 | |||
164 | /* |
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165 | * Execute a command or commands contained in a string. |
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166 | */ |
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167 | |||
168 | void |
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169 | evalstring(s, flag) |
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170 | char *s; |
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171 | int flag; |
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172 | { |
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173 | union node *n; |
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174 | struct stackmark smark; |
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175 | |||
176 | setstackmark(&smark); |
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177 | setinputstring(s, 1); |
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178 | while ((n = parsecmd(0)) != NEOF) { |
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179 | evaltree(n, flag); |
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180 | popstackmark(&smark); |
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181 | } |
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182 | popfile(); |
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183 | popstackmark(&smark); |
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184 | } |
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185 | |||
186 | |||
187 | |||
188 | /* |
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189 | * Evaluate a parse tree. The value is left in the global variable |
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190 | * exitstatus. |
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191 | */ |
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192 | |||
193 | void |
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194 | evaltree(n, flags) |
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195 | union node *n; |
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196 | int flags; |
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197 | { |
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198 | if (n == NULL) { |
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199 | TRACE(("evaltree(NULL) called\n")); |
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200 | exitstatus = 0; |
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201 | goto out; |
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202 | } |
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203 | #ifndef SMALL |
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204 | displayhist = 1; /* show history substitutions done with fc */ |
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205 | #endif |
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206 | TRACE(("evaltree(0x%lx: %d) called\n", (long)n, n->type)); |
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207 | switch (n->type) { |
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208 | case NSEMI: |
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209 | evaltree(n->nbinary.ch1, flags & EV_TESTED); |
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210 | if (evalskip) |
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211 | goto out; |
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212 | evaltree(n->nbinary.ch2, flags); |
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213 | break; |
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214 | case NAND: |
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215 | evaltree(n->nbinary.ch1, EV_TESTED); |
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216 | if (evalskip || exitstatus != 0) { |
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217 | /* don't bomb out on "set -e; false && true" */ |
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218 | flags |= EV_TESTED; |
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219 | goto out; |
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220 | } |
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221 | evaltree(n->nbinary.ch2, flags | EV_TESTED); |
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222 | break; |
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223 | case NOR: |
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224 | evaltree(n->nbinary.ch1, EV_TESTED); |
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225 | if (evalskip || exitstatus == 0) |
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226 | goto out; |
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227 | evaltree(n->nbinary.ch2, flags | EV_TESTED); |
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228 | break; |
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229 | case NREDIR: |
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230 | expredir(n->nredir.redirect); |
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231 | redirect(n->nredir.redirect, REDIR_PUSH); |
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232 | evaltree(n->nredir.n, flags); |
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233 | popredir(); |
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234 | break; |
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235 | case NSUBSHELL: |
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236 | evalsubshell(n, flags); |
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237 | break; |
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238 | case NBACKGND: |
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239 | evalsubshell(n, flags); |
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240 | break; |
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241 | case NIF: { |
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242 | evaltree(n->nif.test, EV_TESTED); |
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243 | if (evalskip) |
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244 | goto out; |
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245 | if (exitstatus == 0) |
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246 | evaltree(n->nif.ifpart, flags); |
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247 | else if (n->nif.elsepart) |
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248 | evaltree(n->nif.elsepart, flags); |
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249 | else |
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250 | exitstatus = 0; |
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251 | break; |
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252 | } |
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253 | case NWHILE: |
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254 | case NUNTIL: |
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255 | evalloop(n, flags); |
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256 | break; |
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257 | case NFOR: |
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258 | evalfor(n, flags); |
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259 | break; |
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260 | case NCASE: |
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261 | evalcase(n, flags); |
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262 | break; |
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263 | case NDEFUN: |
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264 | if (is_special_builtin(n->narg.text)) { |
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265 | outfmt(out2, "%s is a special built-in\n", n->narg.text); |
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266 | exitstatus = 1; |
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267 | break; |
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268 | } |
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269 | defun(n->narg.text, n->narg.next); |
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270 | exitstatus = 0; |
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271 | break; |
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272 | case NNOT: |
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273 | evaltree(n->nnot.com, EV_TESTED); |
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274 | exitstatus = !exitstatus; |
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275 | break; |
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276 | |||
277 | case NPIPE: |
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278 | evalpipe(n); |
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279 | break; |
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280 | case NCMD: |
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281 | evalcommand(n, flags, (struct backcmd *)NULL); |
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282 | break; |
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283 | default: |
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284 | out1fmt("Node type = %d\n", n->type); |
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285 | flushout(&output); |
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286 | break; |
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287 | } |
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288 | out: |
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289 | if (pendingsigs) |
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290 | dotrap(); |
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291 | if ((flags & EV_EXIT) || (eflag && exitstatus && !(flags & EV_TESTED))) |
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292 | exitshell(exitstatus); |
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293 | } |
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294 | |||
295 | |||
296 | STATIC void |
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297 | evalloop(n, flags) |
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298 | union node *n; |
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299 | int flags; |
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300 | { |
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301 | int status; |
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302 | |||
303 | loopnest++; |
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304 | status = 0; |
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305 | for (;;) { |
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306 | evaltree(n->nbinary.ch1, EV_TESTED); |
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307 | if (evalskip) { |
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308 | skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { |
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309 | evalskip = 0; |
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310 | continue; |
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311 | } |
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312 | if (evalskip == SKIPBREAK && --skipcount <= 0) |
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313 | evalskip = 0; |
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314 | break; |
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315 | } |
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316 | if (n->type == NWHILE) { |
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317 | if (exitstatus != 0) |
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318 | break; |
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319 | } else { |
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320 | if (exitstatus == 0) |
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321 | break; |
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322 | } |
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323 | evaltree(n->nbinary.ch2, flags & EV_TESTED); |
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324 | status = exitstatus; |
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325 | if (evalskip) |
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326 | goto skipping; |
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327 | } |
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328 | loopnest--; |
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329 | exitstatus = status; |
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330 | } |
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331 | |||
332 | |||
333 | |||
334 | STATIC void |
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335 | evalfor(n, flags) |
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336 | union node *n; |
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337 | int flags; |
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338 | { |
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339 | struct arglist arglist; |
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340 | union node *argp; |
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341 | struct strlist *sp; |
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342 | struct stackmark smark; |
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343 | |||
344 | setstackmark(&smark); |
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345 | arglist.lastp = &arglist.list; |
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346 | for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { |
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347 | oexitstatus = exitstatus; |
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348 | expandarg(argp, &arglist, EXP_FULL | EXP_TILDE | EXP_RECORD); |
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349 | if (evalskip) |
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350 | goto out; |
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351 | } |
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352 | *arglist.lastp = NULL; |
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353 | |||
354 | exitstatus = 0; |
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355 | loopnest++; |
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356 | for (sp = arglist.list ; sp ; sp = sp->next) { |
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357 | setvar(n->nfor.var, sp->text, 0); |
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358 | evaltree(n->nfor.body, flags & EV_TESTED); |
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359 | if (evalskip) { |
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360 | if (evalskip == SKIPCONT && --skipcount <= 0) { |
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361 | evalskip = 0; |
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362 | continue; |
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363 | } |
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364 | if (evalskip == SKIPBREAK && --skipcount <= 0) |
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365 | evalskip = 0; |
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366 | break; |
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367 | } |
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368 | } |
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369 | loopnest--; |
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370 | out: |
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371 | popstackmark(&smark); |
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372 | } |
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373 | |||
374 | |||
375 | |||
376 | STATIC void |
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377 | evalcase(n, flags) |
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378 | union node *n; |
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379 | int flags; |
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380 | { |
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381 | union node *cp; |
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382 | union node *patp; |
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383 | struct arglist arglist; |
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384 | struct stackmark smark; |
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385 | |||
386 | setstackmark(&smark); |
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387 | arglist.lastp = &arglist.list; |
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388 | oexitstatus = exitstatus; |
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389 | expandarg(n->ncase.expr, &arglist, EXP_TILDE); |
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390 | for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) { |
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391 | for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { |
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392 | if (casematch(patp, arglist.list->text)) { |
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393 | if (evalskip == 0) { |
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394 | evaltree(cp->nclist.body, flags); |
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395 | } |
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396 | goto out; |
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397 | } |
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398 | } |
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399 | } |
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400 | out: |
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401 | popstackmark(&smark); |
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402 | } |
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403 | |||
404 | |||
405 | |||
406 | /* |
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407 | * Kick off a subshell to evaluate a tree. |
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408 | */ |
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409 | |||
410 | STATIC void |
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411 | evalsubshell(n, flags) |
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412 | union node *n; |
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413 | int flags; |
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414 | { |
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415 | struct job *jp; |
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416 | int backgnd = (n->type == NBACKGND); |
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417 | |||
418 | expredir(n->nredir.redirect); |
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419 | jp = makejob(n, 1); |
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420 | if (forkshell(jp, n, backgnd) == 0) { |
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421 | if (backgnd) |
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422 | flags &=~ EV_TESTED; |
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423 | redirect(n->nredir.redirect, 0); |
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424 | evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ |
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425 | } |
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426 | if (! backgnd) { |
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427 | INTOFF; |
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428 | exitstatus = waitforjob(jp); |
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429 | INTON; |
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430 | } |
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431 | } |
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432 | |||
433 | |||
434 | |||
435 | /* |
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436 | * Compute the names of the files in a redirection list. |
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437 | */ |
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438 | |||
439 | STATIC void |
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440 | expredir(n) |
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441 | union node *n; |
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442 | { |
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443 | union node *redir; |
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444 | |||
445 | for (redir = n ; redir ; redir = redir->nfile.next) { |
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446 | struct arglist fn; |
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447 | fn.lastp = &fn.list; |
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448 | oexitstatus = exitstatus; |
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449 | switch (redir->type) { |
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450 | case NFROMTO: |
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451 | case NFROM: |
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452 | case NTO: |
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453 | case NAPPEND: |
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454 | case NTOOV: |
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455 | expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); |
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456 | redir->nfile.expfname = fn.list->text; |
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457 | break; |
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458 | case NFROMFD: |
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459 | case NTOFD: |
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460 | if (redir->ndup.vname) { |
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461 | expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE); |
||
462 | fixredir(redir, fn.list->text, 1); |
||
463 | } |
||
464 | break; |
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465 | } |
||
466 | } |
||
467 | } |
||
468 | |||
469 | |||
470 | |||
471 | /* |
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472 | * Evaluate a pipeline. All the processes in the pipeline are children |
||
473 | * of the process creating the pipeline. (This differs from some versions |
||
474 | * of the shell, which make the last process in a pipeline the parent |
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475 | * of all the rest.) |
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476 | */ |
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477 | |||
478 | STATIC void |
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479 | evalpipe(n) |
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480 | union node *n; |
||
481 | { |
||
482 | struct job *jp; |
||
483 | struct nodelist *lp; |
||
484 | int pipelen; |
||
485 | int prevfd; |
||
486 | int pip[2]; |
||
487 | |||
488 | TRACE(("evalpipe(0x%lx) called\n", (long)n)); |
||
489 | pipelen = 0; |
||
490 | for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) |
||
491 | pipelen++; |
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492 | INTOFF; |
||
493 | jp = makejob(n, pipelen); |
||
494 | prevfd = -1; |
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495 | for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { |
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496 | prehash(lp->n); |
||
497 | pip[1] = -1; |
||
498 | if (lp->next) { |
||
499 | if (pipe(pip) < 0) { |
||
500 | close(prevfd); |
||
501 | error("Pipe call failed"); |
||
502 | } |
||
503 | } |
||
504 | if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { |
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505 | INTON; |
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506 | if (prevfd > 0) { |
||
507 | close(0); |
||
508 | copyfd(prevfd, 0); |
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509 | close(prevfd); |
||
510 | if (pip[0] == 0) { |
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511 | pip[0] = -1; |
||
512 | } |
||
513 | } |
||
514 | if (pip[1] >= 0) { |
||
515 | if (pip[0] >= 0) { |
||
516 | close(pip[0]); |
||
517 | } |
||
518 | if (pip[1] != 1) { |
||
519 | close(1); |
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520 | copyfd(pip[1], 1); |
||
521 | close(pip[1]); |
||
522 | } |
||
523 | } |
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524 | evaltree(lp->n, EV_EXIT); |
||
525 | } |
||
526 | if (prevfd >= 0) |
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527 | close(prevfd); |
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528 | prevfd = pip[0]; |
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529 | close(pip[1]); |
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530 | } |
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531 | INTON; |
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532 | if (n->npipe.backgnd == 0) { |
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533 | INTOFF; |
||
534 | exitstatus = waitforjob(jp); |
||
535 | TRACE(("evalpipe: job done exit status %d\n", exitstatus)); |
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536 | INTON; |
||
537 | } |
||
538 | } |
||
539 | |||
540 | |||
541 | |||
542 | /* |
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543 | * Execute a command inside back quotes. If it's a builtin command, we |
||
544 | * want to save its output in a block obtained from malloc. Otherwise |
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545 | * we fork off a subprocess and get the output of the command via a pipe. |
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546 | * Should be called with interrupts off. |
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547 | */ |
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548 | |||
549 | void |
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550 | evalbackcmd(n, result) |
||
551 | union node *n; |
||
552 | struct backcmd *result; |
||
553 | { |
||
554 | int pip[2]; |
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555 | struct job *jp; |
||
556 | struct stackmark smark; /* unnecessary */ |
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557 | |||
558 | setstackmark(&smark); |
||
559 | result->fd = -1; |
||
560 | result->buf = NULL; |
||
561 | result->nleft = 0; |
||
562 | result->jp = NULL; |
||
563 | if (n == NULL) { |
||
564 | exitstatus = 0; |
||
565 | goto out; |
||
566 | } |
||
567 | #ifdef notyet |
||
568 | /* |
||
569 | * For now we disable executing builtins in the same |
||
570 | * context as the shell, because we are not keeping |
||
571 | * enough state to recover from changes that are |
||
572 | * supposed only to affect subshells. eg. echo "`cd /`" |
||
573 | */ |
||
574 | if (n->type == NCMD) { |
||
575 | exitstatus = oexitstatus; |
||
576 | evalcommand(n, EV_BACKCMD, result); |
||
577 | } else |
||
578 | #endif |
||
579 | { |
||
580 | exitstatus = 0; |
||
581 | if (pipe(pip) < 0) |
||
582 | error("Pipe call failed"); |
||
583 | jp = makejob(n, 1); |
||
584 | if (forkshell(jp, n, FORK_NOJOB) == 0) { |
||
585 | FORCEINTON; |
||
586 | close(pip[0]); |
||
587 | if (pip[1] != 1) { |
||
588 | close(1); |
||
589 | copyfd(pip[1], 1); |
||
590 | close(pip[1]); |
||
591 | } |
||
592 | eflag = 0; |
||
593 | evaltree(n, EV_EXIT); |
||
594 | } |
||
595 | close(pip[1]); |
||
596 | result->fd = pip[0]; |
||
597 | result->jp = jp; |
||
598 | } |
||
599 | out: |
||
600 | popstackmark(&smark); |
||
601 | TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n", |
||
602 | result->fd, result->buf, result->nleft, result->jp)); |
||
603 | } |
||
604 | |||
605 | |||
606 | |||
607 | /* |
||
608 | * Execute a simple command. |
||
609 | */ |
||
610 | |||
611 | STATIC void |
||
612 | evalcommand(cmd, flags, backcmd) |
||
613 | union node *cmd; |
||
614 | int flags; |
||
615 | struct backcmd *backcmd; |
||
616 | { |
||
617 | struct stackmark smark; |
||
618 | union node *argp; |
||
619 | struct arglist arglist; |
||
620 | struct arglist varlist; |
||
621 | char **argv; |
||
622 | int argc; |
||
623 | char **envp; |
||
624 | int varflag; |
||
625 | int pseudovarflag; |
||
626 | struct strlist *sp; |
||
627 | int mode; |
||
628 | int pip[2]; |
||
629 | struct cmdentry cmdentry; |
||
630 | struct job *jp; |
||
631 | struct jmploc jmploc; |
||
632 | struct jmploc *volatile savehandler; |
||
633 | char *volatile savecmdname; |
||
634 | volatile struct shparam saveparam; |
||
635 | struct localvar *volatile savelocalvars; |
||
636 | volatile int e; |
||
637 | char *lastarg; |
||
638 | int not_special; |
||
639 | const char *path; |
||
640 | const char *standard_path; |
||
641 | #if __GNUC__ |
||
642 | /* Avoid longjmp clobbering */ |
||
643 | (void) &argv; |
||
644 | (void) &argc; |
||
645 | (void) &lastarg; |
||
646 | (void) &flags; |
||
647 | (void) ¬_special; |
||
648 | (void) &standard_path; |
||
649 | #endif |
||
650 | |||
651 | /* First expand the arguments. */ |
||
652 | TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags)); |
||
653 | setstackmark(&smark); |
||
654 | arglist.lastp = &arglist.list; |
||
655 | varlist.lastp = &varlist.list; |
||
656 | arglist.list = 0; |
||
657 | varflag = 1; |
||
658 | pseudovarflag = 0; |
||
659 | oexitstatus = exitstatus; |
||
660 | exitstatus = 0; |
||
661 | not_special = 0; |
||
662 | path = pathval(); |
||
663 | standard_path = NULL; |
||
664 | for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { |
||
665 | char *p = argp->narg.text; |
||
666 | if ((varflag || pseudovarflag) && is_name(*p)) { |
||
667 | do { |
||
668 | p++; |
||
669 | } while (is_in_name(*p)); |
||
670 | if (*p == '=') { |
||
671 | if (varflag) |
||
672 | expandarg(argp, &varlist, EXP_VARTILDE); |
||
673 | else |
||
674 | expandarg(argp, &arglist, EXP_VARTILDE); |
||
675 | continue; |
||
676 | } |
||
677 | } |
||
678 | expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); |
||
679 | if (varflag && arglist.list && is_assignment_builtin(arglist.list->text)) |
||
680 | pseudovarflag = 1; |
||
681 | varflag = 0; |
||
682 | } |
||
683 | *arglist.lastp = NULL; |
||
684 | *varlist.lastp = NULL; |
||
685 | expredir(cmd->ncmd.redirect); |
||
686 | argc = 0; |
||
687 | for (sp = arglist.list ; sp ; sp = sp->next) |
||
688 | argc++; |
||
689 | argv = stalloc(sizeof (char *) * (argc + 1)); |
||
690 | |||
691 | for (sp = arglist.list ; sp ; sp = sp->next) { |
||
692 | TRACE(("evalcommand arg: %s\n", sp->text)); |
||
693 | *argv++ = sp->text; |
||
694 | } |
||
695 | *argv = NULL; |
||
696 | lastarg = NULL; |
||
697 | if (iflag && funcnest == 0 && argc > 0) |
||
698 | lastarg = argv[-1]; |
||
699 | argv -= argc; |
||
700 | |||
701 | /* Print the command if xflag is set. */ |
||
702 | if (xflag) { |
||
703 | outc('+', &errout); |
||
704 | for (sp = varlist.list ; sp ; sp = sp->next) { |
||
705 | outc(' ', &errout); |
||
706 | out2str(sp->text); |
||
707 | } |
||
708 | for (sp = arglist.list ; sp ; sp = sp->next) { |
||
709 | outc(' ', &errout); |
||
710 | out2str(sp->text); |
||
711 | } |
||
712 | outc('\n', &errout); |
||
713 | flushout(&errout); |
||
714 | } |
||
715 | |||
716 | /* Now locate the command. */ |
||
717 | if (argc == 0) { |
||
718 | cmdentry.cmdtype = CMDBUILTIN; |
||
719 | cmdentry.u.index = BLTINCMD; |
||
720 | } else { |
||
721 | static const char PATH[] = "PATH="; |
||
722 | const char *oldpath = NULL; |
||
723 | int findflag = DO_ERR; |
||
724 | |||
725 | /* |
||
726 | * Modify the command lookup path, if a PATH= assignment |
||
727 | * is present |
||
728 | */ |
||
729 | for (sp = varlist.list ; sp ; sp = sp->next) |
||
730 | if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) { |
||
731 | path = sp->text + sizeof(PATH) - 1; |
||
732 | findflag |= DO_BRUTE; |
||
733 | } |
||
734 | for(;;) { |
||
735 | find_command(argv[0], &cmdentry, findflag, path); |
||
736 | if (oldpath) { |
||
737 | path = oldpath; |
||
738 | oldpath = NULL; |
||
739 | } |
||
740 | if (cmdentry.cmdtype == CMDUNKNOWN) { /* command not found */ |
||
741 | exitstatus = 127; |
||
742 | flushout(&errout); |
||
743 | goto out; |
||
744 | } |
||
745 | /* implement the bltin builtin here */ |
||
746 | if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) { |
||
747 | not_special = 1; |
||
748 | for(;;) { |
||
749 | argv++; |
||
750 | if (--argc == 0) |
||
751 | break; |
||
752 | if ((cmdentry.u.index = find_builtin(*argv)) < 0) { |
||
753 | outfmt(&errout, "%s: not found\n", *argv); |
||
754 | exitstatus = 127; |
||
755 | flushout(&errout); |
||
756 | goto out; |
||
757 | } |
||
758 | if (cmdentry.u.index != BLTINCMD) |
||
759 | break; |
||
760 | } |
||
761 | } |
||
762 | if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == COMMANDCMD) { |
||
763 | not_special = 1; |
||
764 | argv++; |
||
765 | if (--argc == 0) { |
||
766 | exitstatus = 0; |
||
767 | goto out; |
||
768 | } |
||
769 | if (*argv[0] == '-') { |
||
770 | if (!equal(argv[0], "-p")) { |
||
771 | argv--; |
||
772 | argc++; |
||
773 | break; |
||
774 | } |
||
775 | argv++; |
||
776 | if (--argc == 0) { |
||
777 | exitstatus = 0; |
||
778 | goto out; |
||
779 | } |
||
780 | if (!standard_path) { |
||
781 | standard_path = get_standard_path(); |
||
782 | } |
||
783 | oldpath = path; |
||
784 | path = standard_path; |
||
785 | findflag |= DO_BRUTE; |
||
786 | } |
||
787 | findflag |= DO_NOFUN; |
||
788 | continue; |
||
789 | } |
||
790 | break; |
||
791 | } |
||
792 | } |
||
793 | |||
794 | /* Fork off a child process if necessary. */ |
||
795 | if (cmd->ncmd.backgnd |
||
796 | || (cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0) |
||
797 | || ((flags & EV_BACKCMD) != 0 |
||
798 | && (cmdentry.cmdtype != CMDBUILTIN |
||
799 | || cmdentry.u.index == DOTCMD |
||
800 | || cmdentry.u.index == EVALCMD))) { |
||
801 | jp = makejob(cmd, 1); |
||
802 | mode = cmd->ncmd.backgnd; |
||
803 | if (flags & EV_BACKCMD) { |
||
804 | mode = FORK_NOJOB; |
||
805 | if (pipe(pip) < 0) |
||
806 | error("Pipe call failed"); |
||
807 | } |
||
808 | if (forkshell(jp, cmd, mode) != 0) |
||
809 | goto parent; /* at end of routine */ |
||
810 | if (flags & EV_BACKCMD) { |
||
811 | FORCEINTON; |
||
812 | close(pip[0]); |
||
813 | if (pip[1] != 1) { |
||
814 | close(1); |
||
815 | copyfd(pip[1], 1); |
||
816 | close(pip[1]); |
||
817 | } |
||
818 | } |
||
819 | flags |= EV_EXIT; |
||
820 | } |
||
821 | |||
822 | /* This is the child process if a fork occurred. */ |
||
823 | /* Execute the command. */ |
||
824 | if (cmdentry.cmdtype == CMDFUNCTION) { |
||
825 | #ifdef DEBUG |
||
826 | trputs("Shell function: "); trargs(argv); |
||
827 | #endif |
||
828 | exitstatus = oexitstatus; |
||
829 | redirect(cmd->ncmd.redirect, REDIR_PUSH); |
||
830 | saveparam = shellparam; |
||
831 | shellparam.malloc = 0; |
||
832 | shellparam.nparam = argc - 1; |
||
833 | shellparam.p = argv + 1; |
||
834 | INTOFF; |
||
835 | savelocalvars = localvars; |
||
836 | localvars = NULL; |
||
837 | INTON; |
||
838 | if (setjmp(jmploc.loc)) { |
||
839 | if (exception == EXSHELLPROC) { |
||
840 | freeparam((volatile struct shparam *) |
||
841 | &saveparam); |
||
842 | } else { |
||
843 | saveparam.optind = shellparam.optind; |
||
844 | saveparam.optoff = shellparam.optoff; |
||
845 | freeparam(&shellparam); |
||
846 | shellparam = saveparam; |
||
847 | } |
||
848 | poplocalvars(); |
||
849 | localvars = savelocalvars; |
||
850 | handler = savehandler; |
||
851 | longjmp(handler->loc, 1); |
||
852 | } |
||
853 | savehandler = handler; |
||
854 | handler = &jmploc; |
||
855 | for (sp = varlist.list ; sp ; sp = sp->next) |
||
856 | mklocal(sp->text); |
||
857 | funcnest++; |
||
858 | evaltree(cmdentry.u.func, flags & EV_TESTED); |
||
859 | funcnest--; |
||
860 | INTOFF; |
||
861 | poplocalvars(); |
||
862 | localvars = savelocalvars; |
||
863 | saveparam.optind = shellparam.optind; |
||
864 | saveparam.optoff = shellparam.optoff; |
||
865 | freeparam(&shellparam); |
||
866 | shellparam = saveparam; |
||
867 | handler = savehandler; |
||
868 | popredir(); |
||
869 | INTON; |
||
870 | if (evalskip == SKIPFUNC) { |
||
871 | evalskip = 0; |
||
872 | skipcount = 0; |
||
873 | } |
||
874 | if (flags & EV_EXIT) |
||
875 | exitshell(exitstatus); |
||
876 | } else if (cmdentry.cmdtype == CMDBUILTIN) { |
||
877 | #ifdef DEBUG |
||
878 | trputs("builtin command: "); trargs(argv); |
||
879 | #endif |
||
880 | mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; |
||
881 | if (flags == EV_BACKCMD) { |
||
882 | #if defined(_GNU_SOURCE) && !defined(__UCLIBC__) |
||
883 | openmemout(); |
||
884 | #else |
||
885 | memout.nleft = 0; |
||
886 | memout.nextc = memout.buf; |
||
887 | memout.bufsize = 64; |
||
888 | #endif |
||
889 | mode |= REDIR_BACKQ; |
||
890 | } |
||
891 | redirect(cmd->ncmd.redirect, mode); |
||
892 | savecmdname = commandname; |
||
893 | cmdenviron = varlist.list; |
||
894 | e = -1; |
||
895 | if (setjmp(jmploc.loc)) { |
||
896 | e = exception; |
||
897 | exitstatus = (e == EXINT)? SIGINT+128 : 2; |
||
898 | goto cmddone; |
||
899 | } |
||
900 | savehandler = handler; |
||
901 | handler = &jmploc; |
||
902 | commandname = argv[0]; |
||
903 | argptr = argv + 1; |
||
904 | optptr = NULL; /* initialize nextopt */ |
||
905 | exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); |
||
906 | flushall(); |
||
907 | cmddone: |
||
908 | out1 = &output; |
||
909 | out2 = &errout; |
||
910 | freestdout(); |
||
911 | if (!not_special && is_special_builtin(commandname)) |
||
912 | listsetvar(cmdenviron); |
||
913 | cmdenviron = NULL; |
||
914 | if (e != EXSHELLPROC) { |
||
915 | commandname = savecmdname; |
||
916 | if (flags & EV_EXIT) |
||
917 | exitshell(exitstatus); |
||
918 | } |
||
919 | handler = savehandler; |
||
920 | if (e != -1) { |
||
921 | if ((e != EXERROR && e != EXEXEC) |
||
922 | || cmdentry.u.index == BLTINCMD |
||
923 | || cmdentry.u.index == DOTCMD |
||
924 | || cmdentry.u.index == EVALCMD |
||
925 | #ifndef SMALL |
||
926 | || cmdentry.u.index == HISTCMD |
||
927 | #endif |
||
928 | || cmdentry.u.index == EXECCMD) |
||
929 | exraise(e); |
||
930 | FORCEINTON; |
||
931 | } |
||
932 | if (cmdentry.u.index != EXECCMD) |
||
933 | popredir(); |
||
934 | if (flags == EV_BACKCMD) { |
||
935 | #if defined(_GNU_SOURCE) && !defined(__UCLIBC__) |
||
936 | closememout(); |
||
937 | #endif |
||
938 | backcmd->buf = memout.buf; |
||
939 | #if defined(_GNU_SOURCE) && !defined(__UCLIBC__) |
||
940 | backcmd->nleft = memout.bufsize; |
||
941 | #else |
||
942 | backcmd->nleft = memout.nextc - memout.buf; |
||
943 | #endif |
||
944 | memout.buf = NULL; |
||
945 | } |
||
946 | cmdenviron = NULL; |
||
947 | } else { |
||
948 | #ifdef DEBUG |
||
949 | trputs("normal command: "); trargs(argv); |
||
950 | #endif |
||
951 | clearredir(); |
||
952 | redirect(cmd->ncmd.redirect, 0); |
||
953 | for (sp = varlist.list ; sp ; sp = sp->next) |
||
954 | setvareq(sp->text, VEXPORT|VSTACK); |
||
955 | envp = environment(); |
||
956 | shellexec(argv, envp, path, cmdentry.u.index); |
||
957 | } |
||
958 | goto out; |
||
959 | |||
960 | parent: /* parent process gets here (if we forked) */ |
||
961 | if (mode == 0) { /* argument to fork */ |
||
962 | INTOFF; |
||
963 | exitstatus = waitforjob(jp); |
||
964 | INTON; |
||
965 | } else if (mode == 2) { |
||
966 | backcmd->fd = pip[0]; |
||
967 | close(pip[1]); |
||
968 | backcmd->jp = jp; |
||
969 | } |
||
970 | |||
971 | out: |
||
972 | if (lastarg) |
||
973 | setvar("_", lastarg, 0); |
||
974 | popstackmark(&smark); |
||
975 | |||
976 | if (eflag && exitstatus && !(flags & EV_TESTED)) |
||
977 | exitshell(exitstatus); |
||
978 | } |
||
979 | |||
980 | |||
981 | |||
982 | /* |
||
983 | * Search for a command. This is called before we fork so that the |
||
984 | * location of the command will be available in the parent as well as |
||
985 | * the child. The check for "goodname" is an overly conservative |
||
986 | * check that the name will not be subject to expansion. |
||
987 | */ |
||
988 | |||
989 | STATIC void |
||
990 | prehash(n) |
||
991 | union node *n; |
||
992 | { |
||
993 | struct cmdentry entry; |
||
994 | |||
995 | if (n->type == NCMD && n->ncmd.args) |
||
996 | if (goodname(n->ncmd.args->narg.text)) |
||
997 | find_command(n->ncmd.args->narg.text, &entry, 0, |
||
998 | pathval()); |
||
999 | } |
||
1000 | |||
1001 | |||
1002 | |||
1003 | /* |
||
1004 | * Builtin commands. Builtin commands whose functions are closely |
||
1005 | * tied to evaluation are implemented here. |
||
1006 | */ |
||
1007 | |||
1008 | /* |
||
1009 | * No command given, or a bltin command with no arguments. Set the |
||
1010 | * specified variables. |
||
1011 | */ |
||
1012 | |||
1013 | int |
||
1014 | bltincmd(argc, argv) |
||
1015 | int argc; |
||
1016 | char **argv; |
||
1017 | { |
||
1018 | listsetvar(cmdenviron); |
||
1019 | /* |
||
1020 | * Preserve exitstatus of a previous possible redirection |
||
1021 | * as POSIX mandates |
||
1022 | */ |
||
1023 | return exitstatus; |
||
1024 | } |
||
1025 | |||
1026 | |||
1027 | /* |
||
1028 | * Handle break and continue commands. Break, continue, and return are |
||
1029 | * all handled by setting the evalskip flag. The evaluation routines |
||
1030 | * above all check this flag, and if it is set they start skipping |
||
1031 | * commands rather than executing them. The variable skipcount is |
||
1032 | * the number of loops to break/continue, or the number of function |
||
1033 | * levels to return. (The latter is always 1.) It should probably |
||
1034 | * be an error to break out of more loops than exist, but it isn't |
||
1035 | * in the standard shell so we don't make it one here. |
||
1036 | */ |
||
1037 | |||
1038 | int |
||
1039 | breakcmd(argc, argv) |
||
1040 | int argc; |
||
1041 | char **argv; |
||
1042 | { |
||
1043 | int n = argc > 1 ? number(argv[1]) : 1; |
||
1044 | |||
1045 | if (n > loopnest) |
||
1046 | n = loopnest; |
||
1047 | if (n > 0) { |
||
1048 | evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; |
||
1049 | skipcount = n; |
||
1050 | } |
||
1051 | return 0; |
||
1052 | } |
||
1053 | |||
1054 | |||
1055 | /* |
||
1056 | * The return command. |
||
1057 | */ |
||
1058 | |||
1059 | int |
||
1060 | returncmd(argc, argv) |
||
1061 | int argc; |
||
1062 | char **argv; |
||
1063 | { |
||
1064 | int ret = argc > 1 ? number(argv[1]) : oexitstatus; |
||
1065 | |||
1066 | if (funcnest) { |
||
1067 | evalskip = SKIPFUNC; |
||
1068 | skipcount = 1; |
||
1069 | return ret; |
||
1070 | } |
||
1071 | else { |
||
1072 | /* Do what ksh does; skip the rest of the file */ |
||
1073 | evalskip = SKIPFILE; |
||
1074 | skipcount = 1; |
||
1075 | return ret; |
||
1076 | } |
||
1077 | } |
||
1078 | |||
1079 | |||
1080 | int |
||
1081 | falsecmd(argc, argv) |
||
1082 | int argc; |
||
1083 | char **argv; |
||
1084 | { |
||
1085 | return 1; |
||
1086 | } |
||
1087 | |||
1088 | |||
1089 | int |
||
1090 | truecmd(argc, argv) |
||
1091 | int argc; |
||
1092 | char **argv; |
||
1093 | { |
||
1094 | return 0; |
||
1095 | } |
||
1096 | |||
1097 | |||
1098 | int |
||
1099 | execcmd(argc, argv) |
||
1100 | int argc; |
||
1101 | char **argv; |
||
1102 | { |
||
1103 | if (argc > 1) { |
||
1104 | struct strlist *sp; |
||
1105 | |||
1106 | iflag = 0; /* exit on error */ |
||
1107 | mflag = 0; |
||
1108 | optschanged(); |
||
1109 | for (sp = cmdenviron; sp ; sp = sp->next) |
||
1110 | setvareq(sp->text, VEXPORT|VSTACK); |
||
1111 | shellexec(argv + 1, environment(), pathval(), 0); |
||
1112 | } |
||
1113 | return 0; |
||
1114 | } |
||
1115 | |||
1116 | STATIC int |
||
1117 | is_assignment_builtin (command) |
||
1118 | const char *command; |
||
1119 | { |
||
1120 | static const char *assignment_builtins[] = { |
||
1121 | "alias", "declare", "export", "local", "readonly", "typeset", |
||
1122 | (char *)NULL |
||
1123 | }; |
||
1124 | int i; |
||
1125 | |||
1126 | for (i = 0; assignment_builtins[i]; i++) |
||
1127 | if (strcmp(command, assignment_builtins[i]) == 0) return 1; |
||
1128 | return 0; |
||
1129 | } |
||
1130 | |||
1131 | int |
||
1132 | is_special_builtin(name) |
||
1133 | const char *name; |
||
1134 | { |
||
1135 | static const char *special_builtins[] = { |
||
1136 | "break", ":", ".", "continue", "eval", "exec", "exit", |
||
1137 | "export", "readonly", "return", "set", "shift", "times", |
||
1138 | "trap", "unset", (char *)NULL |
||
1139 | }; |
||
1140 | int i; |
||
1141 | |||
1142 | if (!name) return 0; |
||
1143 | for (i = 0; special_builtins[i]; i++) |
||
1144 | if (equal(name, special_builtins[i])) return 1; |
||
1145 | return 0; |
||
1146 | } |
||
1147 | |||
1148 | STATIC const char * |
||
1149 | get_standard_path() |
||
1150 | { |
||
1151 | char *p; |
||
1152 | size_t len; |
||
1153 | |||
1154 | len = confstr(_CS_PATH, NULL, 0); |
||
1155 | p = stalloc(len + 2); |
||
1156 | *p = '\0'; |
||
1157 | confstr(_CS_PATH, p, len); |
||
1158 | return p; |
||
1159 | } |