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                 trace_printf("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          * Propagate this setting to external programs.
  66          */
  67         setenv(EXEC_PATH_ENVIRONMENT, exec_path, 1);
  68 }
  69
  70
  71 /* Returns the highest-priority, location to look for git programs. */
  72 const char *git_exec_path(void)
  73 {
  74         const char *env;
  75
  76         if (argv_exec_path)
  77                 return argv_exec_path;
  78
  79         env = getenv(EXEC_PATH_ENVIRONMENT);
  80         if (env && *env) {
  81                 return env;
  82         }
  83
  84         return system_path(GIT_EXEC_PATH);
  85 }
  86
  87 static void add_path(struct strbuf *out, const char *path)
  88 {
  89         if (path && *path) {
  90                 if (is_absolute_path(path))
  91                         strbuf_addstr(out, path);
  92                 else
  93                         strbuf_addstr(out, make_nonrelative_path(path));
  94
  95                 strbuf_addch(out, PATH_SEP);
  96         }
  97 }
  98
  99 void setup_path(void)
 100 {
 101         const char *old_path = getenv("PATH");
 102         struct strbuf new_path = STRBUF_INIT;
 103
 104         add_path(&new_path, git_exec_path());
 105         add_path(&new_path, argv0_path);
 106
 107         if (old_path)
 108                 strbuf_addstr(&new_path, old_path);
 109         else
 110                 strbuf_addstr(&new_path, "/usr/local/bin:/usr/bin:/bin");
 111
 112         setenv("PATH", new_path.buf, 1);
 113
 114         strbuf_release(&new_path);
 115 }
 116
 117 const char **prepare_git_cmd(const char **argv)
 118 {
 119         int argc;
 120         const char **nargv;
 121
 122         for (argc = 0; argv[argc]; argc++)
 123                 ; /* just counting */
 124         nargv = xmalloc(sizeof(*nargv) * (argc + 2));
 125
 126         nargv[0] = "git";
 127         for (argc = 0; argv[argc]; argc++)
 128                 nargv[argc + 1] = argv[argc];
 129         nargv[argc + 1] = NULL;
 130         return nargv;
 131 }
 132
 133 int execv_git_cmd(const char **argv) {
 134         const char **nargv = prepare_git_cmd(argv);
 135         trace_argv_printf(nargv, "trace: exec:");
 136
 137         /* execvp() can only ever return if it fails */
 138         execvp("git", (char **)nargv);
 139
 140         trace_printf("trace: exec failed: %s\n", strerror(errno));
 141
 142         free(nargv);
 143         return -1;
 144 }
 145
 146
 147 int execl_git_cmd(const char *cmd,...)
 148 {
 149         int argc;
 150         const char *argv[MAX_ARGS + 1];
 151         const char *arg;
 152         va_list param;
 153
 154         va_start(param, cmd);
 155         argv[0] = cmd;
 156         argc = 1;
 157         while (argc < MAX_ARGS) {
 158                 arg = argv[argc++] = va_arg(param, char *);
 159                 if (!arg)
 160                         break;
 161         }
 162         va_end(param);
 163         if (MAX_ARGS <= argc)
 164                 return error("too many args to run %s", cmd);
 165
 166         argv[argc] = NULL;
 167         return execv_git_cmd(argv);
 168 }