f22995393a
Since the macro PATH_MAX is not defined on every system (GNU/Hurd being one of those who do not define it), we remove all references to this macro. Instead, we use a buffer of arbitraty size and grow it when needed to contain paths.
102 lines
2.5 KiB
C
102 lines
2.5 KiB
C
#include <unistd.h>
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#include <string.h>
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#include <stdio.h>
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#include <limits.h>
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#include <stdlib.h>
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#include <errno.h>
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#include "libi3.h"
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/*
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* This function returns the absolute path to the executable it is running in.
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*
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* The implementation follows http://stackoverflow.com/a/933996/712014
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*
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* Returned value must be freed by the caller.
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*/
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char *get_exe_path(const char *argv0) {
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size_t destpath_size = 1024;
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size_t tmp_size = 1024;
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char *destpath = smalloc(destpath_size);
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char *tmp = smalloc(tmp_size);
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#if defined(__linux__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
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/* Linux and Debian/kFreeBSD provide /proc/self/exe */
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#if defined(__linux__) || defined(__FreeBSD_kernel__)
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const char *exepath = "/proc/self/exe";
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#elif defined(__FreeBSD__)
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const char *exepath = "/proc/curproc/file";
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#endif
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ssize_t linksize;
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while ((linksize = readlink(exepath, destpath, destpath_size)) == destpath_size) {
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destpath_size = destpath_size * 2;
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destpath = srealloc(destpath, destpath_size);
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}
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if (linksize != -1) {
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/* readlink() does not NULL-terminate strings, so we have to. */
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destpath[linksize] = '\0';
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free(tmp);
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return destpath;
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}
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#endif
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/* argv[0] is most likely a full path if it starts with a slash. */
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if (argv0[0] == '/') {
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free(tmp);
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free(destpath);
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return sstrdup(argv0);
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}
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/* if argv[0] contains a /, prepend the working directory */
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if (strchr(argv0, '/') != NULL) {
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char *retgcwd;
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while ((retgcwd = getcwd(tmp, tmp_size)) == NULL && errno == ERANGE) {
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tmp_size = tmp_size * 2;
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tmp = srealloc(tmp, tmp_size);
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}
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if (retgcwd != NULL) {
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free(destpath);
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sasprintf(&destpath, "%s/%s", tmp, argv0);
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free(tmp);
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return destpath;
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}
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}
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/* Fall back to searching $PATH (or _CS_PATH in absence of $PATH). */
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char *path = getenv("PATH");
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if (path == NULL) {
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/* _CS_PATH is typically something like "/bin:/usr/bin" */
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while (confstr(_CS_PATH, tmp, tmp_size) > tmp_size) {
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tmp_size = tmp_size * 2;
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tmp = srealloc(tmp, tmp_size);
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}
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sasprintf(&path, ":%s", tmp);
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} else {
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path = strdup(path);
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}
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const char *component;
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char *str = path;
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while (1) {
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if ((component = strtok(str, ":")) == NULL)
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break;
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str = NULL;
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free(destpath);
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sasprintf(&destpath, "%s/%s", component, argv0);
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/* Of course this is not 100% equivalent to actually exec()ing the
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* binary, but meh. */
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if (access(destpath, X_OK) == 0) {
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free(path);
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free(tmp);
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return destpath;
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}
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}
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free(destpath);
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free(path);
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free(tmp);
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/* Last resort: maybe it’s in /usr/bin? */
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return sstrdup("/usr/bin/i3-nagbar");
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}
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