--- /dev/null
+/*
+ * Copyright (c) 2005 Junio C Hamano
+ */
+
+#include "cache.h"
+#include "diff.h"
+
+static int diff_output_format = DIFF_FORMAT_HUMAN;
+static int detect_rename = 0;
+static int diff_setup_opt = 0;
+static int diff_score_opt = 0;
+static const char *pickaxe = NULL;
+static int pickaxe_opts = 0;
+static int diff_break_opt = -1;
+static const char *orderfile = NULL;
+
+static char *diff_stages_usage =
+"git-diff-stages [-p] [-r] [-z] [-M] [-C] [-R] [-S<string>] [-O<orderfile>] <stage1> <stage2> [<path>...]";
+
+int main(int ac, const char **av)
+{
+ int stage1, stage2, i;
+
+ read_cache();
+ while (1 < ac && av[1][0] == '-') {
+ const char *arg = av[1];
+ if (!strcmp(arg, "-r"))
+ ; /* as usual */
+ else if (!strcmp(arg, "-p"))
+ diff_output_format = DIFF_FORMAT_PATCH;
+ else if (!strncmp(arg, "-B", 2)) {
+ if ((diff_break_opt = diff_scoreopt_parse(arg)) == -1)
+ usage(diff_stages_usage);
+ }
+ else if (!strncmp(arg, "-M", 2)) {
+ detect_rename = DIFF_DETECT_RENAME;
+ if ((diff_score_opt = diff_scoreopt_parse(arg)) == -1)
+ usage(diff_stages_usage);
+ }
+ else if (!strncmp(arg, "-C", 2)) {
+ detect_rename = DIFF_DETECT_COPY;
+ if ((diff_score_opt = diff_scoreopt_parse(arg)) == -1)
+ usage(diff_stages_usage);
+ }
+ else if (!strcmp(arg, "-z"))
+ diff_output_format = DIFF_FORMAT_MACHINE;
+ else if (!strcmp(arg, "-R"))
+ diff_setup_opt |= DIFF_SETUP_REVERSE;
+ else if (!strncmp(arg, "-S", 2))
+ pickaxe = arg + 2;
+ else if (!strncmp(arg, "-O", 2))
+ orderfile = arg + 2;
+ else if (!strcmp(arg, "--pickaxe-all"))
+ pickaxe_opts = DIFF_PICKAXE_ALL;
+ else
+ usage(diff_stages_usage);
+ ac--; av++;
+ }
+
+ if (ac < 3 ||
+ sscanf(av[1], "%d", &stage1) != 1 ||
+ ! (0 <= stage1 && stage1 <= 3) ||
+ sscanf(av[2], "%d", &stage2) != 1 ||
+ ! (0 <= stage2 && stage2 <= 3))
+ usage(diff_stages_usage);
+
+ av += 3; /* The rest from av[0] are for paths restriction. */
+ diff_setup(diff_setup_opt);
+
+ i = 0;
+ while (i < active_nr) {
+ struct cache_entry *ce, *stages[4] = { NULL, };
+ struct cache_entry *one, *two;
+ const char *name;
+ int len;
+ ce = active_cache[i];
+ len = ce_namelen(ce);
+ name = ce->name;
+ for (;;) {
+ int stage = ce_stage(ce);
+ stages[stage] = ce;
+ if (active_nr <= ++i)
+ break;
+ ce = active_cache[i];
+ if (ce_namelen(ce) != len ||
+ memcmp(name, ce->name, len))
+ break;
+ }
+ one = stages[stage1];
+ two = stages[stage2];
+ if (!one && !two)
+ continue;
+ if (!one)
+ diff_addremove('+', ntohl(two->ce_mode),
+ two->sha1, name, NULL);
+ else if (!two)
+ diff_addremove('-', ntohl(one->ce_mode),
+ one->sha1, name, NULL);
+ else if (memcmp(one->sha1, two->sha1, 20) ||
+ (one->ce_mode != two->ce_mode))
+ diff_change(ntohl(one->ce_mode), ntohl(two->ce_mode),
+ one->sha1, two->sha1, name, NULL);
+ }
+
+ diffcore_std(av,
+ detect_rename, diff_score_opt,
+ pickaxe, pickaxe_opts,
+ diff_break_opt,
+ orderfile);
+ diff_flush(diff_output_format, 1);
+ return 0;
+}