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