newlib/winsup/testsuite/libltp/lib/search_path.c

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2000-09-03 05:52:30 +02:00
/*
* (C) COPYRIGHT CRAY RESEARCH, INC.
* UNPUBLISHED PROPRIETARY INFORMATION.
* ALL RIGHTS RESERVED.
*/
/**********************************************************
*
* UNICOS Feature Test and Evaluation - Cray Research, Inc.
*
* FUNCTION NAME : search_path
*
* FUNCTION TITLE : search PATH locations for desired filename
*
* SYNOPSIS:
* int search_path(cmd, res_path, access_mode, fullpath)
* char *cmd;
* char *res_path;
* int access_mode;
* int fullpath;
*
* AUTHOR : Richard Logan
*
* INITIAL RELEASE : UNICOS 7.0
*
* DESCRIPTION
* Search_path will walk through PATH and attempt to find "cmd". If cmd is
* a full or relative path, it is checked but PATH locations are not scanned.
* search_path will put the resulting path in res_path. It is assumed
* that res_path points to a string that is at least PATH_MAX
* (or MAXPATHLEN on the suns) in size. Access_mode is just as is
* says, the mode to be used on access to determine if cmd can be found.
* If fullpath is set, res_path will contain the full path to cmd.
* If it is not set, res_path may or may not contain the full path to cmd.
* If fullpath is not set, the path in PATH prepended to cmd is used,
* which could be a relative path. If fullpath is set, the current
* directory is prepended to path/cmd before access is called.
* If cmd is found, search_path will return 0. If cmd cannot be
* found, 1 is returned. If an error has occurred, -1 is returned
* and an error mesg is placed in res_path.
* If the length of path/cmd is larger then PATH_MAX, then that path
* location is skipped.
*
*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#**/
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <sys/errno.h>
#include <sys/param.h>
#include <sys/stat.h>
extern int errno;
struct stat stbuf;
#ifndef AS_CMD
#define AS_CMD 0
#endif
/*
* Make sure PATH_MAX is defined. Define it to MAXPATHLEN, if set. Otherwise
* set it to 1024.
*/
#ifndef PATH_MAX
#ifndef MAXPATHLEN
#define PATH_MAX 1024
#else /* MAXPATHLEN */
#define PATH_MAX MAXPATHLEN
#endif /* MAXPATHLEN */
#endif /* PATH_MAX */
#if AS_CMD
main(argc, argv)
int argc;
char **argv;
{
char path[PATH_MAX];
int ind;
if (argc <= 1 ) {
printf("missing argument\n");
exit(1);
}
for(ind=1;ind < argc; ind++) {
if ( search_path(argv[ind], path, F_OK, 0) < 0 ) {
printf("ERROR: %s\n", path);
}
else {
printf("path of %s is %s\n", argv[ind], path);
}
}
}
#endif
/*
*/
int
search_path(cmd, res_path, access_mode, fullpath)
char *cmd; /* The requested filename */
char *res_path; /* The resulting path or error mesg */
int access_mode; /* the mode used by access(2) */
int fullpath; /* if set, cwd will be prepended to all non-full paths */
{
char *cp; /* used to scan PATH for directories */
int ret; /* return value from access */
char *pathenv;
char tmppath[PATH_MAX];
char curpath[PATH_MAX];
char *path;
int lastpath;
int toolong=0;
#if DEBUG
printf("search_path: cmd = %s, access_mode = %d, fullpath = %d\n", cmd, access_mode, fullpath);
#endif
/*
* full or relative path was given
*/
if ( (cmd[0] == '/') || ( (cp=strchr(cmd, '/')) != NULL )) {
if ( access(cmd, access_mode) == 0 ) {
if ( cmd[0] != '/' ) { /* relative path */
if ( getcwd(curpath, PATH_MAX) == NULL ) {
strcpy(res_path, curpath);
return -1;
}
if ( (strlen(curpath) + strlen(cmd) + 1) > (size_t)PATH_MAX ) {
sprintf(res_path, "cmd (as relative path) and cwd is longer than %d",
PATH_MAX);
return -1;
}
sprintf(res_path, "%s/%s", curpath, cmd);
}
else
strcpy(res_path, cmd);
return 0;
}
else {
sprintf(res_path, "file %s not found", cmd);
return -1;
}
}
/* get the PATH variable */
if ( (pathenv=getenv("PATH")) == NULL) {
/* no path to scan, return */
sprintf(res_path, "Unable to get PATH env. variable");
return -1;
}
/*
* walk through each path in PATH.
* Each path in PATH is placed in tmppath.
* pathenv cannot be modified since it will affect PATH.
* If a signal came in while we have modified the PATH
* memory, we could create a problem for the caller.
*/
curpath[0]='\0';
cp = pathenv;
path = pathenv;
lastpath = 0;
for (;;) {
if ( lastpath )
break;
if ( cp != pathenv )
path = ++cp; /* already set on first iteration */
/* find end of current path */
for (; ((*cp != ':') && (*cp != '\0')); cp++);
/*
* copy path to tmppath so it can be NULL terminated
* and so we do not modify path memory.
*/
strncpy(tmppath, path, (cp-path) );
tmppath[cp-path]='\0';
#if DEBUG
printf("search_path: tmppath = %s\n", tmppath);
#endif
if ( *cp == '\0' )
lastpath=1; /* this is the last path entry */
/* Check lengths so not to overflow res_path */
if ( strlen(tmppath) + strlen(cmd) + 2 > (size_t)PATH_MAX ) {
toolong++;
continue;
}
sprintf(res_path, "%s/%s", tmppath, cmd);
#if DEBUG
printf("search_path: res_path = '%s'\n", res_path);
#endif
/* if the path is not full at this point, prepend the current
* path to get the full path.
* Note: this could not be wise to do when under a protected
* directory.
*/
if ( fullpath && res_path[0] != '/' ) { /* not a full path */
if ( curpath[0] == '\0' ) {
if ( getcwd(curpath, PATH_MAX) == NULL ) {
strcpy(res_path, curpath);
return -1;
}
}
if ( (strlen(curpath) + strlen(res_path) + 2) > (size_t)PATH_MAX ) {
toolong++;
continue;
}
sprintf(tmppath, "%s/%s", curpath, res_path);
strcpy(res_path, tmppath);
#if DEBUG
printf("search_path: full res_path= '%s'\n", res_path);
#endif
}
if ( (ret=access(res_path, access_mode)) == 0 ) {
#if DEBUG
printf("search_path: found res_path = %s\n", res_path);
#endif
return 0;
}
}
/* return failure */
if ( toolong )
sprintf(res_path,
"Unable to find file, %d path/file strings were too long", toolong);
else
strcpy(res_path, "Unable to find file");
return 1; /* not found */
}