Andrew's git - gitweb.git/blob - builtin/difftool.c

   1/*
   2 * "git difftool" builtin command
   3 *
   4 * This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
   5 * git-difftool--helper script.
   6 *
   7 * This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git.
   8 * The GIT_DIFF* variables are exported for use by git-difftool--helper.
   9 *
  10 * Any arguments that are unknown to this script are forwarded to 'git diff'.
  11 *
  12 * Copyright (C) 2016 Johannes Schindelin
  13 */
  14#include "builtin.h"
  15#include "run-command.h"
  16#include "exec_cmd.h"
  17
  18/*
  19 * NEEDSWORK: this function can go once the legacy-difftool Perl script is
  20 * retired.
  21 *
  22 * We intentionally avoid reading the config directly here, to avoid messing up
  23 * the GIT_* environment variables when we need to fall back to exec()ing the
  24 * Perl script.
  25 */
  26static int use_builtin_difftool(void) {
  27        struct child_process cp = CHILD_PROCESS_INIT;
  28        struct strbuf out = STRBUF_INIT;
  29        int ret;
  30
  31        argv_array_pushl(&cp.args,
  32                         "config", "--bool", "difftool.usebuiltin", NULL);
  33        cp.git_cmd = 1;
  34        if (capture_command(&cp, &out, 6))
  35                return 0;
  36        strbuf_trim(&out);
  37        ret = !strcmp("true", out.buf);
  38        strbuf_release(&out);
  39        return ret;
  40}
  41
  42int cmd_difftool(int argc, const char **argv, const char *prefix)
  43{
  44        /*
  45         * NEEDSWORK: Once the builtin difftool has been tested enough
  46         * and git-legacy-difftool.perl is retired to contrib/, this preamble
  47         * can be removed.
  48         */
  49        if (!use_builtin_difftool()) {
  50                const char *path = mkpath("%s/git-legacy-difftool",
  51                                          git_exec_path());
  52
  53                if (sane_execvp(path, (char **)argv) < 0)
  54                        die_errno("could not exec %s", path);
  55
  56                return 0;
  57        }
  58        prefix = setup_git_directory();
  59        trace_repo_setup(prefix);
  60        setup_work_tree();
  61
  62        die("TODO");
  63}