| 0,0 → 1,492 |
|---|
| /* $NetBSD: redir.c,v 1.22 2000/05/22 10:18:47 elric Exp $ */ |
| |
| /*- |
| * Copyright (c) 1991, 1993 |
| * The Regents of the University of California. All rights reserved. |
| * |
| * This code is derived from software contributed to Berkeley by |
| * Kenneth Almquist. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. All advertising materials mentioning features or use of this software |
| * must display the following acknowledgement: |
| * This product includes software developed by the University of |
| * California, Berkeley and its contributors. |
| * 4. Neither the name of the University nor the names of its contributors |
| * may be used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #include <sys/cdefs.h> |
| #ifndef lint |
| #if 0 |
| static char sccsid[] = "@(#)redir.c 8.2 (Berkeley) 5/4/95"; |
| #else |
| __RCSID("$NetBSD: redir.c,v 1.22 2000/05/22 10:18:47 elric Exp $"); |
| #endif |
| #endif /* not lint */ |
| |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <sys/param.h> /* PIPE_BUF */ |
| #include <signal.h> |
| #include <string.h> |
| #include <fcntl.h> |
| #include <errno.h> |
| #include <unistd.h> |
| #include <stdlib.h> |
| |
| /* |
| * Code for dealing with input/output redirection. |
| */ |
| |
| #include "shell.h" |
| #include "nodes.h" |
| #include "jobs.h" |
| #include "expand.h" |
| #include "redir.h" |
| #include "output.h" |
| #include "memalloc.h" |
| #include "error.h" |
| #include "options.h" |
| |
| |
| #define EMPTY -2 /* marks an unused slot in redirtab */ |
| #ifndef PIPE_BUF |
| # define PIPESIZE 4096 /* amount of buffering in a pipe */ |
| #else |
| # define PIPESIZE PIPE_BUF |
| #endif |
| |
| |
| MKINIT |
| struct redirtab { |
| struct redirtab *next; |
| short renamed[10]; |
| }; |
| |
| |
| MKINIT struct redirtab *redirlist; |
| |
| /* |
| * We keep track of whether or not fd0 has been redirected. This is for |
| * background commands, where we want to redirect fd0 to /dev/null only |
| * if it hasn't already been redirected. |
| */ |
| int fd0_redirected = 0; |
| |
| /* |
| * We also keep track of where fd2 goes. |
| */ |
| int fd2 = 2; |
| |
| STATIC int openredirect (union node *); |
| STATIC void dupredirect (union node *, int, char[10 ]); |
| STATIC int openhere (union node *); |
| STATIC int noclobberopen (const char *); |
| |
| |
| /* |
| * Process a list of redirection commands. If the REDIR_PUSH flag is set, |
| * old file descriptors are stashed away so that the redirection can be |
| * undone by calling popredir. If the REDIR_BACKQ flag is set, then the |
| * standard output, and the standard error if it becomes a duplicate of |
| * stdout, is saved in memory. |
| */ |
| |
| void |
| redirect(redir, flags) |
| union node *redir; |
| int flags; |
| { |
| union node *n; |
| struct redirtab *sv = NULL; |
| int i; |
| int fd; |
| int newfd; |
| int try; |
| char memory[10]; /* file descriptors to write to memory */ |
| |
| for (i = 10 ; --i >= 0 ; ) |
| memory[i] = 0; |
| memory[1] = flags & REDIR_BACKQ; |
| if (flags & REDIR_PUSH) { |
| sv = ckmalloc(sizeof (struct redirtab)); |
| for (i = 0 ; i < 10 ; i++) |
| sv->renamed[i] = EMPTY; |
| sv->next = redirlist; |
| redirlist = sv; |
| } |
| for (n = redir ; n ; n = n->nfile.next) { |
| fd = n->nfile.fd; |
| try = 0; |
| if ((n->nfile.type == NTOFD || n->nfile.type == NFROMFD) && |
| n->ndup.dupfd == fd) |
| continue; /* redirect from/to same file descriptor */ |
| |
| INTOFF; |
| newfd = openredirect(n); |
| if (((flags & REDIR_PUSH) && sv->renamed[fd] == EMPTY) || |
| (fd == fd2)) { |
| if (newfd == fd) { |
| try++; |
| } else if ((i = fcntl(fd, F_DUPFD, 10)) == -1) { |
| switch (errno) { |
| case EBADF: |
| if (!try) { |
| dupredirect(n, newfd, memory); |
| try++; |
| break; |
| } |
| /* FALLTHROUGH*/ |
| default: |
| if (newfd >= 0) { |
| close(newfd); |
| } |
| INTON; |
| error("%d: %s", fd, strerror(errno)); |
| /* NOTREACHED */ |
| } |
| } |
| if (!try) { |
| close(fd); |
| if (flags & REDIR_PUSH) { |
| sv->renamed[fd] = i; |
| } |
| if (fd == fd2) { |
| fd2 = i; |
| } |
| } |
| } else if (fd != newfd) { |
| close(fd); |
| } |
| if (fd == 0) |
| fd0_redirected++; |
| if (!try) |
| dupredirect(n, newfd, memory); |
| INTON; |
| } |
| if (memory[1]) |
| out1 = &memout; |
| if (memory[2]) |
| out2 = &memout; |
| } |
| |
| |
| STATIC int |
| openredirect(redir) |
| union node *redir; |
| { |
| char *fname; |
| int f; |
| |
| switch (redir->nfile.type) { |
| case NFROM: |
| fname = redir->nfile.expfname; |
| if ((f = open(fname, O_RDONLY)) < 0) |
| goto eopen; |
| break; |
| case NFROMTO: |
| fname = redir->nfile.expfname; |
| if ((f = open(fname, O_RDWR|O_CREAT|O_TRUNC, 0666)) < 0) |
| goto ecreate; |
| break; |
| case NTO: |
| /* Take care of noclobber mode. */ |
| if (Cflag) { |
| fname = redir->nfile.expfname; |
| if ((f = noclobberopen(fname)) < 0) |
| goto ecreate; |
| break; |
| } |
| case NTOOV: |
| fname = redir->nfile.expfname; |
| #ifdef O_CREAT |
| if ((f = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) < 0) |
| goto ecreate; |
| #else |
| if ((f = creat(fname, 0666)) < 0) |
| goto ecreate; |
| #endif |
| break; |
| case NAPPEND: |
| fname = redir->nfile.expfname; |
| #ifdef O_APPEND |
| if ((f = open(fname, O_WRONLY|O_CREAT|O_APPEND, 0666)) < 0) |
| goto ecreate; |
| #else |
| if ((f = open(fname, O_WRONLY)) < 0 |
| && (f = creat(fname, 0666)) < 0) |
| goto ecreate; |
| lseek(f, (off_t)0, 2); |
| #endif |
| break; |
| case NTOFD: |
| case NFROMFD: |
| f = -1; |
| break; |
| case NHERE: |
| case NXHERE: |
| f = openhere(redir); |
| break; |
| default: |
| abort(); |
| } |
| |
| return f; |
| ecreate: |
| error("cannot create %s: %s", fname, errmsg(errno, E_CREAT)); |
| eopen: |
| error("cannot open %s: %s", fname, errmsg(errno, E_OPEN)); |
| } |
| |
| |
| STATIC void |
| dupredirect(redir, f, memory) |
| union node *redir; |
| int f; |
| char memory[10]; |
| { |
| int fd = redir->nfile.fd; |
| |
| memory[fd] = 0; |
| if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) { |
| if (redir->ndup.dupfd >= 0) { /* if not ">&-" */ |
| if (memory[redir->ndup.dupfd]) |
| memory[fd] = 1; |
| else |
| copyfd(redir->ndup.dupfd, fd); |
| } |
| return; |
| } |
| |
| if (f != fd) { |
| copyfd(f, fd); |
| close(f); |
| } |
| return; |
| } |
| |
| |
| /* |
| * Handle here documents. Normally we fork off a process to write the |
| * data to a pipe. If the document is short, we can stuff the data in |
| * the pipe without forking. |
| */ |
| |
| STATIC int |
| openhere(redir) |
| union node *redir; |
| { |
| int pip[2]; |
| int len = 0; |
| |
| if (pipe(pip) < 0) |
| error("Pipe call failed"); |
| if (redir->type == NHERE) { |
| len = strlen(redir->nhere.doc->narg.text); |
| if (len <= PIPESIZE) { |
| xwrite(pip[1], redir->nhere.doc->narg.text, len); |
| goto out; |
| } |
| } |
| if (forkshell((struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) { |
| close(pip[0]); |
| signal(SIGINT, SIG_IGN); |
| signal(SIGQUIT, SIG_IGN); |
| signal(SIGHUP, SIG_IGN); |
| #ifdef SIGTSTP |
| signal(SIGTSTP, SIG_IGN); |
| #endif |
| signal(SIGPIPE, SIG_DFL); |
| if (redir->type == NHERE) |
| xwrite(pip[1], redir->nhere.doc->narg.text, len); |
| else |
| expandhere(redir->nhere.doc, pip[1]); |
| _exit(0); |
| } |
| out: |
| close(pip[1]); |
| return pip[0]; |
| } |
| |
| |
| |
| /* |
| * Undo the effects of the last redirection. |
| */ |
| |
| void |
| popredir() { |
| struct redirtab *rp = redirlist; |
| int i; |
| |
| INTOFF; |
| for (i = 0 ; i < 10 ; i++) { |
| if (rp->renamed[i] != EMPTY) { |
| if (i == 0) |
| fd0_redirected--; |
| close(i); |
| if (rp->renamed[i] >= 0) { |
| copyfd(rp->renamed[i], i); |
| close(rp->renamed[i]); |
| } |
| if (rp->renamed[i] == fd2) { |
| fd2 = i; |
| } |
| } |
| } |
| redirlist = rp->next; |
| ckfree(rp); |
| INTON; |
| } |
| |
| /* |
| * Undo all redirections. Called on error or interrupt. |
| */ |
| |
| #ifdef mkinit |
| |
| INCLUDE "redir.h" |
| |
| RESET { |
| while (redirlist) |
| popredir(); |
| } |
| |
| SHELLPROC { |
| clearredir(); |
| } |
| |
| #endif |
| |
| /* Return true if fd 0 has already been redirected at least once. */ |
| int |
| fd0_redirected_p () { |
| return fd0_redirected != 0; |
| } |
| |
| /* |
| * Discard all saved file descriptors. |
| */ |
| |
| void |
| clearredir() { |
| struct redirtab *rp; |
| int i; |
| |
| for (rp = redirlist ; rp ; rp = rp->next) { |
| for (i = 0 ; i < 10 ; i++) { |
| if (rp->renamed[i] >= 0) { |
| close(rp->renamed[i]); |
| if (rp->renamed[i] == fd2) { |
| fd2 = -1; |
| } |
| } |
| rp->renamed[i] = EMPTY; |
| } |
| } |
| } |
| |
| |
| |
| /* |
| * Copy a file descriptor to be >= to. Returns -1 |
| * if the source file descriptor is closed, EMPTY if there are no unused |
| * file descriptors left. |
| */ |
| |
| int |
| copyfd(from, to) |
| int from; |
| int to; |
| { |
| int newfd; |
| |
| newfd = fcntl(from, F_DUPFD, to); |
| if (newfd < 0) { |
| if (errno == EMFILE) |
| return EMPTY; |
| else |
| error("%d: %s", from, strerror(errno)); |
| } |
| return newfd; |
| } |
| |
| /* |
| * Open a file in noclobber mode. |
| * The code was copied from bash. |
| */ |
| int |
| noclobberopen(fname) |
| const char *fname; |
| { |
| int r, fd; |
| struct stat finfo, finfo2; |
| |
| /* |
| * If the file exists and is a regular file, return an error |
| * immediately. |
| */ |
| r = stat(fname, &finfo); |
| if (r == 0 && S_ISREG(finfo.st_mode)) { |
| errno = EEXIST; |
| return -1; |
| } |
| |
| /* |
| * If the file was not present (r != 0), make sure we open it |
| * exclusively so that if it is created before we open it, our open |
| * will fail. Make sure that we do not truncate an existing file. |
| * Note that we don't turn on O_EXCL unless the stat failed -- if the |
| * file was not a regular file, we leave O_EXCL off. |
| */ |
| if (r != 0) |
| return open(fname, O_WRONLY|O_CREAT|O_EXCL, 0666); |
| fd = open(fname, O_WRONLY|O_CREAT, 0666); |
| |
| /* If the open failed, return the file descriptor right away. */ |
| if (fd < 0) |
| return fd; |
| |
| /* |
| * OK, the open succeeded, but the file may have been changed from a |
| * non-regular file to a regular file between the stat and the open. |
| * We are assuming that the O_EXCL open handles the case where FILENAME |
| * did not exist and is symlinked to an existing file between the stat |
| * and open. |
| */ |
| |
| /* |
| * If we can open it and fstat the file descriptor, and neither check |
| * revealed that it was a regular file, and the file has not been |
| * replaced, return the file descriptor. |
| */ |
| if (fstat(fd, &finfo2) == 0 && !S_ISREG(finfo2.st_mode) && |
| finfo.st_dev == finfo2.st_dev && finfo.st_ino == finfo2.st_ino) |
| return fd; |
| |
| /* The file has been replaced. badness. */ |
| close(fd); |
| errno = EEXIST; |
| return -1; |
| } |