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                 /*
  32                  * RUNTIME_PREFIX requested, but prefix computation failed.
  33                  * Using static fallback.
  34                  */
  35         }
  36 #endif
  37
  38         strbuf_addf(&d, "%s/%s", prefix, path);
  39         path = strbuf_detach(&d, NULL);
  40         return path;
  41 }
  42
  43 const char *git_extract_argv0_path(const char *argv0)
  44 {
  45         const char *slash;
  46
  47         if (!argv0 || !*argv0)
  48                 return NULL;
  49         slash = argv0 + strlen(argv0);
  50
  51         while (argv0 <= slash && !is_dir_sep(*slash))
  52                 slash--;
  53
  54         if (slash >= argv0) {
  55                 argv0_path = xstrndup(argv0, slash - argv0);
  56                 return slash + 1;
  57         }
  58
  59         return argv0;
  60 }
  61
  62 void git_set_argv_exec_path(const char *exec_path)
  63 {
  64         argv_exec_path = exec_path;
  65         /*
  66          * Propagate this setting to external programs.
  67          */
  68         setenv(EXEC_PATH_ENVIRONMENT, exec_path, 1);
  69 }
  70
  71
  72 /* Returns the highest-priority, location to look for git programs. */
  73 const char *git_exec_path(void)
  74 {
  75         const char *env;
  76
  77         if (argv_exec_path)
  78                 return argv_exec_path;
  79
  80         env = getenv(EXEC_PATH_ENVIRONMENT);
  81         if (env && *env) {
  82                 return env;
  83         }
  84
  85         return system_path(GIT_EXEC_PATH);
  86 }
  87
  88 static void add_path(struct strbuf *out, const char *path)
  89 {
  90         if (path && *path) {
  91                 if (is_absolute_path(path))
  92                         strbuf_addstr(out, path);
  93                 else
  94                         strbuf_addstr(out, make_nonrelative_path(path));
  95
  96                 strbuf_addch(out, PATH_SEP);
  97         }
  98 }
  99
 100 void setup_path(void)
 101 {
 102         const char *old_path = getenv("PATH");
 103         struct strbuf new_path = STRBUF_INIT;
 104
 105         add_path(&new_path, git_exec_path());
 106         add_path(&new_path, argv0_path);
 107
 108         if (old_path)
 109                 strbuf_addstr(&new_path, old_path);
 110         else
 111                 strbuf_addstr(&new_path, "/usr/local/bin:/usr/bin:/bin");
 112
 113         setenv("PATH", new_path.buf, 1);
 114
 115         strbuf_release(&new_path);
 116 }
 117
 118 const char **prepare_git_cmd(const char **argv)
 119 {
 120         int argc;
 121         const char **nargv;
 122
 123         for (argc = 0; argv[argc]; argc++)
 124                 ; /* just counting */
 125         nargv = xmalloc(sizeof(*nargv) * (argc + 2));
 126
 127         nargv[0] = "git";
 128         for (argc = 0; argv[argc]; argc++)
 129                 nargv[argc + 1] = argv[argc];
 130         nargv[argc + 1] = NULL;
 131         return nargv;
 132 }
 133
 134 int execv_git_cmd(const char **argv) {
 135         const char **nargv = prepare_git_cmd(argv);
 136         trace_argv_printf(nargv, "trace: exec:");
 137
 138         /* execvp() can only ever return if it fails */
 139         execvp("git", (char **)nargv);
 140
 141         trace_printf("trace: exec failed: %s\n", strerror(errno));
 142
 143         free(nargv);
 144         return -1;
 145 }
 146
 147
 148 int execl_git_cmd(const char *cmd,...)
 149 {
 150         int argc;
 151         const char *argv[MAX_ARGS + 1];
 152         const char *arg;
 153         va_list param;
 154
 155         va_start(param, cmd);
 156         argv[0] = cmd;
 157         argc = 1;
 158         while (argc < MAX_ARGS) {
 159                 arg = argv[argc++] = va_arg(param, char *);
 160                 if (!arg)
 161                         break;
 162         }
 163         va_end(param);
 164         if (MAX_ARGS <= argc)
 165                 return error("too many args to run %s", cmd);
 166
 167         argv[argc] = NULL;
 168         return execv_git_cmd(argv);
 169 }