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