diff options: add --color

This patch is a slightly adjusted version of Junio's patch:
http://www.gelato.unsw.edu.au/archives/git/0604/19354.html

However, instead of using a config variable, this patch makes it available
as a diff option.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/diff.c b/diff.c
index 9e9cfc8b75b7b761980b0d32cb0c516ea3505ba3..bc32a4aa29171af6ca268a54cde881934079de83 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -25,6 +25,20 @@ int git_diff_config(const char *var, const char *value)
        return git_default_config(var, value);
 }
 
+enum color_diff {
+       DIFF_PLAIN = 0,
+       DIFF_METAINFO = 1,
+       DIFF_FILE_OLD = 2,
+       DIFF_FILE_NEW = 3,
+};
+
+static const char *diff_colors[] = {
+       "\033[0;0m",
+       "\033[1;35m",
+       "\033[1;31m",
+       "\033[1;34m",
+};
+
 static char *quote_one(const char *str)
 {
        int needlen;
@@ -177,23 +191,54 @@ static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 }
 
 struct emit_callback {
+       struct xdiff_emit_state xm;
+       int nparents, color_diff;
        const char **label_path;
 };
 
-static int fn_out(void *priv, mmbuffer_t *mb, int nbuf)
+static inline void color_diff(int diff_use_color, enum color_diff ix)
+{
+       if (diff_use_color)
+               fputs(diff_colors[ix], stdout);
+}
+
+static void fn_out_consume(void *priv, char *line, unsigned long len)
 {
        int i;
        struct emit_callback *ecbdata = priv;
 
        if (ecbdata->label_path[0]) {
+               color_diff(ecbdata->color_diff, DIFF_METAINFO);
                printf("--- %s\n", ecbdata->label_path[0]);
+               color_diff(ecbdata->color_diff, DIFF_METAINFO);
                printf("+++ %s\n", ecbdata->label_path[1]);
                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
        }
-       for (i = 0; i < nbuf; i++)
-               if (!fwrite(mb[i].ptr, mb[i].size, 1, stdout))
-                       return -1;
-       return 0;
+
+       /* This is not really necessary for now because
+        * this codepath only deals with two-way diffs.
+        */
+       for (i = 0; i < len && line[i] == '@'; i++)
+               ;
+       if (2 <= i && i < len && line[i] == ' ') {
+               ecbdata->nparents = i - 1;
+               color_diff(ecbdata->color_diff, DIFF_METAINFO);
+       }
+       else if (len < ecbdata->nparents)
+               color_diff(ecbdata->color_diff, DIFF_PLAIN);
+       else {
+               int nparents = ecbdata->nparents;
+               int color = DIFF_PLAIN;
+               for (i = 0; i < nparents && len; i++) {
+                       if (line[i] == '-')
+                               color = DIFF_FILE_OLD;
+                       else if (line[i] == '+')
+                               color = DIFF_FILE_NEW;
+               }
+               color_diff(ecbdata->color_diff, color);
+       }
+       fwrite(line, len, 1, stdout);
+       color_diff(ecbdata->color_diff, DIFF_PLAIN);
 }
 
 static char *pprint_rename(const char *a, const char *b)
@@ -549,25 +594,35 @@ static void builtin_diff(const char *name_a,
        b_two = quote_two("b/", name_b);
        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
+       color_diff(o->color_diff, DIFF_METAINFO);
        printf("diff --git %s %s\n", a_one, b_two);
        if (lbl[0][0] == '/') {
                /* /dev/null */
+               color_diff(o->color_diff, DIFF_METAINFO);
                printf("new file mode %06o\n", two->mode);
-               if (xfrm_msg && xfrm_msg[0])
+               if (xfrm_msg && xfrm_msg[0]) {
+                       color_diff(o->color_diff, DIFF_METAINFO);
                        puts(xfrm_msg);
+               }
        }
        else if (lbl[1][0] == '/') {
                printf("deleted file mode %06o\n", one->mode);
-               if (xfrm_msg && xfrm_msg[0])
+               if (xfrm_msg && xfrm_msg[0]) {
+                       color_diff(o->color_diff, DIFF_METAINFO);
                        puts(xfrm_msg);
+               }
        }
        else {
                if (one->mode != two->mode) {
+                       color_diff(o->color_diff, DIFF_METAINFO);
                        printf("old mode %06o\n", one->mode);
+                       color_diff(o->color_diff, DIFF_METAINFO);
                        printf("new mode %06o\n", two->mode);
                }
-               if (xfrm_msg && xfrm_msg[0])
+               if (xfrm_msg && xfrm_msg[0]) {
+                       color_diff(o->color_diff, DIFF_METAINFO);
                        puts(xfrm_msg);
+               }
                /*
                 * we do not run diff between different kind
                 * of objects.
@@ -575,6 +630,7 @@ static void builtin_diff(const char *name_a,
                if ((one->mode ^ two->mode) & S_IFMT)
                        goto free_ab_and_return;
                if (complete_rewrite) {
+                       color_diff(o->color_diff, DIFF_PLAIN);
                        emit_rewrite_diff(name_a, name_b, one, two);
                        goto free_ab_and_return;
                }
@@ -602,7 +658,9 @@ static void builtin_diff(const char *name_a,
                xdemitcb_t ecb;
                struct emit_callback ecbdata;
 
+               memset(&ecbdata, 0, sizeof(ecbdata));
                ecbdata.label_path = lbl;
+               ecbdata.color_diff = o->color_diff;
                xpp.flags = XDF_NEED_MINIMAL;
                xecfg.ctxlen = o->context;
                xecfg.flags = XDL_EMIT_FUNCNAMES;
@@ -612,8 +670,9 @@ static void builtin_diff(const char *name_a,
                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
                else if (!strncmp(diffopts, "-u", 2))
                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
-               ecb.outf = fn_out;
+               ecb.outf = xdiff_outf;
                ecb.priv = &ecbdata;
+               ecbdata.xm.consume = fn_out_consume;
                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
        }
 
@@ -1456,6 +1515,8 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                else if (40 < options->abbrev)
                        options->abbrev = 40;
        }
+       else if (!strcmp(arg, "--color"))
+               options->color_diff = 1;
        else
                return 0;
        return 1;

diff --git a/diff.h b/diff.h
index 4fc597c59421b7558e0beb0f2994e15950592aaa..de9de574e78693d27ff911d882030a59407a99d5 100644 (file)
--- a/diff.h
+++ b/diff.h
@@ -32,7 +32,8 @@ struct diff_options {
                 full_index:1,
                 silent_on_remove:1,
                 find_copies_harder:1,
-                summary:1;
+                summary:1,
+                color_diff:1;
        int context;
        int break_opt;
        int detect_rename;

diff --git a/pager.c b/pager.c
index 9a30939016620072f319b5fef81d0c913513a641..2d186e8bde1067a62c9615e8d7f0368f98442ca4 100644 (file)
--- a/pager.c
+++ b/pager.c
@@ -46,7 +46,7 @@ void setup_pager(void)
        close(fd[0]);
        close(fd[1]);
 
-       setenv("LESS", "-S", 0);
+       setenv("LESS", "-RS", 0);
        run_pager(pager);
        die("unable to execute pager '%s'", pager);
        exit(255);