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Ignore whitespace Rev 3345 → Rev 3346

/trunk/uspace/app/bdsh/exec.c
0,0 → 1,126
/* Copyright (c) 2008, Tim Post <tinkertim@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 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.
*
* Neither the name of the original program's authors 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
*/
 
/* The VERY basics of execute in place support. These are buggy, leaky
* and not nearly done. Only here for beta testing!! You were warned!!
* TODO:
* Hash command lookups to save time
* Create a running pointer to **path and advance/rewind it as we go */
 
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
 
#include "config.h"
#include "util.h"
#include "exec.h"
#include "errors.h"
 
/* FIXME: Just have find_command() return an allocated string */
char *found;
 
/* work-around for access() */
unsigned int try_access(const char *f)
{
int fd;
 
fd = open(f, O_RDONLY);
if (fd > -1) {
close(fd);
return 0;
} else
return -1;
}
 
/* Returns the full path of "cmd" if cmd is found, else just hand back
* cmd as it was presented */
char *find_command(char *cmd)
{
char *path_orig, *path_tok;
char *path[PATH_MAX];
int n = 0, i = 0;
size_t x = strlen(cmd) + 2;
 
found = (char *)malloc(PATH_MAX);
 
/* The user has specified a full or relative path, just give it back. */
if (-1 != try_access(cmd)) {
return (char *) cmd;
}
path_orig = PATH;
path_tok = cli_strdup(path_orig);
 
/* Extract the PATH env to a path[] array */
path[n] = cli_strtok(path_tok, PATH_DELIM);
while (NULL != path[n]) {
if ((strlen(path[n]) + x ) > PATH_MAX) {
cli_error(CL_ENOTSUP,
"Segment %d of path is too large, search ends at segment %d",
n, n-1);
break;
}
path[++n] = cli_strtok(NULL, PATH_DELIM);
}
 
/* We now have n places to look for the command */
for (i=0; path[i]; i++) {
memset(found, 0, sizeof(found));
snprintf(found, PATH_MAX, "%s/%s", path[i], cmd);
if (-1 != try_access(found)) {
free(path_tok);
return (char *) found;
}
}
 
/* We didn't find it, just give it back as-is. */
free(path_tok);
return (char *) cmd;
}
 
unsigned int try_exec(char *cmd, char **argv)
{
task_id_t tid;
char *tmp;
 
tmp = cli_strdup(find_command(cmd));
free(found);
 
tid = task_spawn((const char *)tmp, (const char **)argv);
free(tmp);
 
if (tid == 0) {
cli_error(CL_EEXEC, "Can not spawn %s", cmd);
return 1;
} else {
return 0;
}
}