154 lines
4.6 KiB
C
154 lines
4.6 KiB
C
/* Locating a program in PATH.
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Copyright (C) 2001-2004, 2006-2026 Free Software Foundation, Inc.
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Written by Bruno Haible <haible@clisp.cons.org>, 2001.
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This file is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 of the
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License, or (at your option) any later version.
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This file is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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#include <config.h>
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/* Specification. */
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#include "findprog.h"
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#if !(defined _WIN32 || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__)
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# include <sys/stat.h>
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#endif
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/* Avoid collision between findprog.c and findprog-lgpl.c. */
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#if IN_FINDPROG_LGPL || ! GNULIB_FINDPROG_LGPL
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#if !IN_FINDPROG_LGPL
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# include "xalloc.h"
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#endif
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#include "concat-filename.h"
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const char *
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find_in_path (const char *progname)
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{
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#if defined _WIN32 || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__
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/* Native Windows, Cygwin, OS/2, DOS */
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/* The searching rules with .COM, .EXE, .BAT, .CMD etc. suffixes are
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too complicated. Leave it to the OS. */
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return progname;
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#else
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/* Unix */
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if (strchr (progname, '/') != NULL)
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/* If progname contains a slash, it is either absolute or relative to
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the current directory. PATH is not used. */
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return progname;
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char *path = getenv ("PATH");
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if (path == NULL || *path == '\0')
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/* If PATH is not set, the default search path is implementation
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dependent. */
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return progname;
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/* Make a copy, to prepare for destructive modifications. */
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# if !IN_FINDPROG_LGPL
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path = xstrdup (path);
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# else
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path = strdup (path);
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if (path == NULL)
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/* Out of memory. */
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return progname;
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# endif
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for (char *path_rest = path; ; )
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{
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/* Extract next directory in PATH. */
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const char *dir = path_rest;
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char *cp;
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for (cp = path_rest; *cp != '\0' && *cp != ':'; cp++)
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;
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bool last = (*cp == '\0');
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*cp = '\0';
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/* Empty PATH components designate the current directory. */
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if (dir == cp)
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dir = ".";
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/* Concatenate dir and progname. */
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char *progpathname;
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# if !IN_FINDPROG_LGPL
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progpathname = xconcatenated_filename (dir, progname, NULL);
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# else
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progpathname = concatenated_filename (dir, progname, NULL);
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if (progpathname == NULL)
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{
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/* Out of memory. */
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free (path);
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return progname;
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}
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# endif
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/* On systems which have the eaccess() system call, let's use it.
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On other systems, let's hope that this program is not installed
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setuid or setgid, so that it is ok to call access() despite its
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design flaw. */
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if (eaccess (progpathname, X_OK) == 0)
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{
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/* Check that the progpathname does not point to a directory. */
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struct stat statbuf;
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if (stat (progpathname, &statbuf) >= 0
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&& ! S_ISDIR (statbuf.st_mode))
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{
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/* Found! */
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if (streq (progpathname, progname))
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{
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free (progpathname);
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/* Add the "./" prefix for real, that xconcatenated_filename()
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optimized away. This avoids a second PATH search when the
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caller uses execlp/execvp. */
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# if !IN_FINDPROG_LGPL
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progpathname = XNMALLOC (2 + strlen (progname) + 1, char);
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# else
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progpathname = (char *) malloc (2 + strlen (progname) + 1);
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if (progpathname == NULL)
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{
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/* Out of memory. */
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free (path);
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return progname;
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}
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# endif
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progpathname[0] = '.';
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progpathname[1] = '/';
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memcpy (progpathname + 2, progname, strlen (progname) + 1);
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}
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free (path);
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return progpathname;
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}
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}
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free (progpathname);
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if (last)
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break;
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path_rest = cp + 1;
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}
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/* Not found in PATH. An error will be signalled at the first call. */
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free (path);
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return progname;
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#endif
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}
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#endif
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