exec_cmd.c

   1 #include "cache.h"
   2 #include "exec_cmd.h"
   3 #include "quote.h"
   4 #define MAX_ARGS        32
   5
   6 extern char **environ;
   7 static const char *argv_exec_path;
   8 static const char *argv0_path;
   9
  10 const char *system_path(const char *path)
  11 {
  12         static const char *prefix;
  13
  14         if (is_absolute_path(path)) {
  15                 return path;
  16         }
  17
  18 #ifdef RUNTIME_PREFIX
  19         assert(argv0_path);
  20         assert(is_absolute_path(argv0_path));
  21
  22         if (!prefix) {
  23                 const char *strip[] = {
  24                         GIT_EXEC_PATH,
  25                         BINDIR,
  26                         0
  27                 };
  28                 const char **s;
  29
  30                 for (s = strip; *s; s++) {
  31                         const char *sargv = argv0_path + strlen(argv0_path);
  32                         const char *ss = *s + strlen(*s);
  33                         while (argv0_path < sargv && *s < ss
  34                                 && (*sargv == *ss ||
  35                                     (is_dir_sep(*sargv) && is_dir_sep(*ss)))) {
  36                                 sargv--;
  37                                 ss--;
  38                         }
  39                         if (*s == ss) {
  40                                 struct strbuf d = STRBUF_INIT;
  41                                 /* We also skip the trailing directory separator. */
  42                                 assert(sargv - argv0_path - 1 >= 0);
  43                                 strbuf_add(&d, argv0_path, sargv - argv0_path - 1);
  44                                 prefix = strbuf_detach(&d, NULL);
  45                                 break;
  46                         }
  47                 }
  48         }
  49
  50         if (!prefix) {
  51                 prefix = PREFIX;
  52                 fprintf(stderr, "RUNTIME_PREFIX requested, "
  53                                 "but prefix computation failed.  "
  54                                 "Using static fallback '%s'.\n", prefix);
  55         }
  56 #else
  57         prefix = PREFIX;
  58 #endif
  59
  60         struct strbuf d = STRBUF_INIT;
  61         strbuf_addf(&d, "%s/%s", prefix, path);
  62         path = strbuf_detach(&d, NULL);
  63         return path;
  64 }
  65
  66 const char *git_extract_argv0_path(const char *argv0)
  67 {
  68         const char *slash = argv0 + strlen(argv0);
  69
  70         do
  71                 --slash;
  72         while (slash >= argv0 && !is_dir_sep(*slash));
  73
  74         if (slash >= argv0) {
  75                 argv0_path = xstrndup(argv0, slash - argv0);
  76                 return slash + 1;
  77         }
  78
  79         return argv0;
  80 }
  81
  82 void git_set_argv_exec_path(const char *exec_path)
  83 {
  84         argv_exec_path = exec_path;
  85 }
  86
  87
  88 /* Returns the highest-priority, location to look for git programs. */
  89 const char *git_exec_path(void)
  90 {
  91         const char *env;
  92
  93         if (argv_exec_path)
  94                 return argv_exec_path;
  95
  96         env = getenv(EXEC_PATH_ENVIRONMENT);
  97         if (env && *env) {
  98                 return env;
  99         }
 100
 101         return system_path(GIT_EXEC_PATH);
 102 }
 103
 104 static void add_path(struct strbuf *out, const char *path)
 105 {
 106         if (path && *path) {
 107                 if (is_absolute_path(path))
 108                         strbuf_addstr(out, path);
 109                 else
 110                         strbuf_addstr(out, make_nonrelative_path(path));
 111
 112                 strbuf_addch(out, PATH_SEP);
 113         }
 114 }
 115
 116 void setup_path(void)
 117 {
 118         const char *old_path = getenv("PATH");
 119         struct strbuf new_path = STRBUF_INIT;
 120
 121         add_path(&new_path, git_exec_path());
 122         add_path(&new_path, argv0_path);
 123
 124         if (old_path)
 125                 strbuf_addstr(&new_path, old_path);
 126         else
 127                 strbuf_addstr(&new_path, "/usr/local/bin:/usr/bin:/bin");
 128
 129         setenv("PATH", new_path.buf, 1);
 130
 131         strbuf_release(&new_path);
 132 }
 133
 134 const char **prepare_git_cmd(const char **argv)
 135 {
 136         int argc;
 137         const char **nargv;
 138
 139         for (argc = 0; argv[argc]; argc++)
 140                 ; /* just counting */
 141         nargv = xmalloc(sizeof(*nargv) * (argc + 2));
 142
 143         nargv[0] = "git";
 144         for (argc = 0; argv[argc]; argc++)
 145                 nargv[argc + 1] = argv[argc];
 146         nargv[argc + 1] = NULL;
 147         return nargv;
 148 }
 149
 150 int execv_git_cmd(const char **argv) {
 151         const char **nargv = prepare_git_cmd(argv);
 152         trace_argv_printf(nargv, "trace: exec:");
 153
 154         /* execvp() can only ever return if it fails */
 155         execvp("git", (char **)nargv);
 156
 157         trace_printf("trace: exec failed: %s\n", strerror(errno));
 158
 159         free(nargv);
 160         return -1;
 161 }
 162
 163
 164 int execl_git_cmd(const char *cmd,...)
 165 {
 166         int argc;
 167         const char *argv[MAX_ARGS + 1];
 168         const char *arg;
 169         va_list param;
 170
 171         va_start(param, cmd);
 172         argv[0] = cmd;
 173         argc = 1;
 174         while (argc < MAX_ARGS) {
 175                 arg = argv[argc++] = va_arg(param, char *);
 176                 if (!arg)
 177                         break;
 178         }
 179         va_end(param);
 180         if (MAX_ARGS <= argc)
 181                 return error("too many args to run %s", cmd);
 182
 183         argv[argc] = NULL;
 184         return execv_git_cmd(argv);
 185 }