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                 if (is_absolute_path(path))
  89                         strbuf_addstr(out, path);
  90                 else
  91                         strbuf_addstr(out, absolute_path(path));
  92
  93                 strbuf_addch(out, PATH_SEP);
  94         }
  95 }
  96
  97 void setup_path(void)
  98 {
  99         const char *old_path = getenv("PATH");
 100         struct strbuf new_path = STRBUF_INIT;
 101
 102         add_path(&new_path, git_exec_path());
 103         add_path(&new_path, argv0_path);
 104
 105         if (old_path)
 106                 strbuf_addstr(&new_path, old_path);
 107         else
 108                 strbuf_addstr(&new_path, _PATH_DEFPATH);
 109
 110         setenv("PATH", new_path.buf, 1);
 111
 112         strbuf_release(&new_path);
 113 }
 114
 115 const char **prepare_git_cmd(const char **argv)
 116 {
 117         int argc;
 118         const char **nargv;
 119
 120         for (argc = 0; argv[argc]; argc++)
 121                 ; /* just counting */
 122         nargv = xmalloc(sizeof(*nargv) * (argc + 2));
 123
 124         nargv[0] = "git";
 125         for (argc = 0; argv[argc]; argc++)
 126                 nargv[argc + 1] = argv[argc];
 127         nargv[argc + 1] = NULL;
 128         return nargv;
 129 }
 130
 131 int execv_git_cmd(const char **argv) {
 132         const char **nargv = prepare_git_cmd(argv);
 133         trace_argv_printf(nargv, "trace: exec:");
 134
 135         /* execvp() can only ever return if it fails */
 136         sane_execvp("git", (char **)nargv);
 137
 138         trace_printf("trace: exec failed: %s\n", strerror(errno));
 139
 140         free(nargv);
 141         return -1;
 142 }
 143
 144
 145 int execl_git_cmd(const char *cmd,...)
 146 {
 147         int argc;
 148         const char *argv[MAX_ARGS + 1];
 149         const char *arg;
 150         va_list param;
 151
 152         va_start(param, cmd);
 153         argv[0] = cmd;
 154         argc = 1;
 155         while (argc < MAX_ARGS) {
 156                 arg = argv[argc++] = va_arg(param, char *);
 157                 if (!arg)
 158                         break;
 159         }
 160         va_end(param);
 161         if (MAX_ARGS <= argc)
 162                 return error("too many args to run %s", cmd);
 163
 164         argv[argc] = NULL;
 165         return execv_git_cmd(argv);
 166 }