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
  47         slash = find_last_dir_sep(argv0);
  48
  49         if (slash) {
  50                 argv0_path = xstrndup(argv0, slash - argv0);
  51                 return slash + 1;
  52         }
  53
  54         return argv0;
  55 }
  56
  57 void git_set_argv_exec_path(const char *exec_path)
  58 {
  59         argv_exec_path = exec_path;
  60         /*
  61          * Propagate this setting to external programs.
  62          */
  63         setenv(EXEC_PATH_ENVIRONMENT, exec_path, 1);
  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                 strbuf_add_absolute_path(out, path);
  87                 strbuf_addch(out, PATH_SEP);
  88         }
  89 }
  90
  91 void setup_path(void)
  92 {
  93         const char *old_path = getenv("PATH");
  94         struct strbuf new_path = STRBUF_INIT;
  95
  96         add_path(&new_path, git_exec_path());
  97
  98         if (old_path)
  99                 strbuf_addstr(&new_path, old_path);
 100         else
 101                 strbuf_addstr(&new_path, _PATH_DEFPATH);
 102
 103         setenv("PATH", new_path.buf, 1);
 104
 105         strbuf_release(&new_path);
 106 }
 107
 108 const char **prepare_git_cmd(const char **argv)
 109 {
 110         int argc;
 111         const char **nargv;
 112
 113         for (argc = 0; argv[argc]; argc++)
 114                 ; /* just counting */
 115         nargv = xmalloc(sizeof(*nargv) * (argc + 2));
 116
 117         nargv[0] = "git";
 118         for (argc = 0; argv[argc]; argc++)
 119                 nargv[argc + 1] = argv[argc];
 120         nargv[argc + 1] = NULL;
 121         return nargv;
 122 }
 123
 124 int execv_git_cmd(const char **argv) {
 125         const char **nargv = prepare_git_cmd(argv);
 126         trace_argv_printf(nargv, "trace: exec:");
 127
 128         /* execvp() can only ever return if it fails */
 129         sane_execvp("git", (char **)nargv);
 130
 131         trace_printf("trace: exec failed: %s\n", strerror(errno));
 132
 133         free(nargv);
 134         return -1;
 135 }
 136
 137
 138 int execl_git_cmd(const char *cmd,...)
 139 {
 140         int argc;
 141         const char *argv[MAX_ARGS + 1];
 142         const char *arg;
 143         va_list param;
 144
 145         va_start(param, cmd);
 146         argv[0] = cmd;
 147         argc = 1;
 148         while (argc < MAX_ARGS) {
 149                 arg = argv[argc++] = va_arg(param, char *);
 150                 if (!arg)
 151                         break;
 152         }
 153         va_end(param);
 154         if (MAX_ARGS <= argc)
 155                 return error("too many args to run %s", cmd);
 156
 157         argv[argc] = NULL;
 158         return execv_git_cmd(argv);
 159 }