exec_cmd.c

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