pretty_print_commit: add different formats

You can ask to print out "raw" format (full headers, full body),
"medium" format (author and date, full body) or "short" format
(author only, condensed body).

Use "git-rev-list --pretty=short HEAD | less -S" for an example.

commit.c

+#include <ctype.h>
 #include "tag.h"
 #include "commit.h"
 #include "cache.h"
@@ -193,12 +194,12 @@ static int get_one_line(const char *msg, unsigned long len)
 	return ret;
 }
 
-static int add_author_info(char *buf, const char *line, int len)
+static int add_author_info(enum cmit_fmt fmt, char *buf, const char *line, int len)
 {
 	char *date;
 	unsigned int namelen;
 	unsigned long time;
-	int tz;
+	int tz, ret;
 
 	line += strlen("author ");
 	date = strchr(line, '>');
@@ -208,14 +209,22 @@ static int add_author_info(char *buf, const char *line, int len)
 	time = strtoul(date, &date, 10);
 	tz = strtol(date, NULL, 10);
 
-	return sprintf(buf, "Author: %.*s\nDate:   %s\n",
-		namelen, line,
-		show_date(time, tz));
+	ret = sprintf(buf, "Author: %.*s\n", namelen, line);
+	if (fmt == CMIT_FMT_MEDIUM)
+		ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
+	return ret;
+}
+
+static int is_empty_line(const char *line, int len)
+{
+	while (len && isspace(line[len-1]))
+		len--;
+	return !len;
 }
 
-unsigned long pretty_print_commit(const char *msg, unsigned long len, char *buf, unsigned long space)
+unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space)
 {
-	int hdr = 1;
+	int hdr = 1, body = 0;
 	unsigned long offset = 0;
 
 	for (;;) {
@@ -237,13 +246,30 @@ unsigned long pretty_print_commit(const char *msg, unsigned long len, char *buf,
 
 		msg += linelen;
 		len -= linelen;
-		if (linelen == 1)
-			hdr = 0;
 		if (hdr) {
+			if (linelen == 1) {
+				hdr = 0;
+				buf[offset++] = '\n';
+				continue;
+			}
+			if (fmt == CMIT_FMT_RAW) {
+				memcpy(buf + offset, line, linelen);
+				offset += linelen;
+				continue;
+			}
 			if (!memcmp(line, "author ", 7))
-				offset += add_author_info(buf + offset, line, linelen);
+				offset += add_author_info(fmt, buf + offset, line, linelen);
 			continue;
 		}
+
+		if (is_empty_line(line, linelen)) {
+			if (!body)
+				continue;
+			if (fmt == CMIT_FMT_SHORT)
+				break;
+		} else {
+			body = 1;
+		}
 		memset(buf + offset, ' ', 4);
 		memcpy(buf + offset + 4, line, linelen);
 		offset += linelen + 4;

commit.h

@@ -32,7 +32,15 @@ void free_commit_list(struct commit_list *list);
 
 void sort_by_date(struct commit_list **list);
 
-extern unsigned long pretty_print_commit(const char *msg, unsigned long len, char *buf, unsigned long space);
+/* Commit formats */
+enum cmit_fmt {
+	CMIT_FMT_RAW,
+	CMIT_FMT_MEDIUM,
+	CMIT_FMT_DEFAULT = CMIT_FMT_MEDIUM,
+	CMIT_FMT_SHORT
+};
+
+extern unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space);
 
 
 /** Removes the first commit from a list sorted by date, and adds all

diff-tree.c

@@ -19,6 +19,7 @@ static int diff_break_opt = -1;
 static const char *orderfile = NULL;
 static const char *header = NULL;
 static const char *header_prefix = "";
+static enum cmit_fmt commit_format = CMIT_FMT_RAW;
 
 // What paths are we interested in?
 static int nr_paths = 0;
@@ -321,7 +322,7 @@ static char *generate_header(const char *commit, const char *parent, const char
 
 	offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
 	if (verbose_header) {
-		offset += pretty_print_commit(msg, len, this_header + offset, sizeof(this_header) - offset);
+		offset += pretty_print_commit(commit_format, msg, len, this_header + offset, sizeof(this_header) - offset);
 		this_header[offset++] = '\n';
 		this_header[offset++] = 0;
 	}

rev-list.c

@@ -15,12 +15,12 @@ static const char rev_list_usage[] =
 
 static int verbose_header = 0;
 static int show_parents = 0;
-static int pretty_print = 0;
 static int hdr_termination = 0;
 static const char *prefix = "";
 static unsigned long max_age = -1;
 static unsigned long min_age = -1;
 static int max_count = -1;
+static enum cmit_fmt commit_format = CMIT_FMT_RAW;
 
 static void show_commit(struct commit *commit)
 {
@@ -34,13 +34,9 @@ static void show_commit(struct commit *commit)
 	}
 	putchar('\n');
 	if (verbose_header) {
-		const char *buf = commit->buffer;
-		if (pretty_print) {
-			static char pretty_header[16384];
-			pretty_print_commit(commit->buffer, ~0, pretty_header, sizeof(pretty_header));
-			buf = pretty_header;
-		}
-		printf("%s%c", buf, hdr_termination);
+		static char pretty_header[16384];
+		pretty_print_commit(commit_format, commit->buffer, ~0, pretty_header, sizeof(pretty_header));
+		printf("%s%c", pretty_header, hdr_termination);
 	}
 }
 
@@ -103,6 +99,20 @@ struct commit_list *limit_list(struct commit_list *list)
 	return newlist;
 }
 
+static enum cmit_fmt get_commit_format(const char *arg)
+{
+	if (!*arg)
+		return CMIT_FMT_DEFAULT;
+	if (!strcmp(arg, "=raw"))
+		return CMIT_FMT_RAW;
+	if (!strcmp(arg, "=medium"))
+		return CMIT_FMT_MEDIUM;
+	if (!strcmp(arg, "=short"))
+		return CMIT_FMT_SHORT;
+	usage(rev_list_usage);	
+}			
+
+
 int main(int argc, char **argv)
 {
 	struct commit_list *list = NULL;
@@ -130,9 +140,9 @@ int main(int argc, char **argv)
 			verbose_header = 1;
 			continue;
 		}
-		if (!strcmp(arg, "--pretty")) {
+		if (!strncmp(arg, "--pretty", 8)) {
+			commit_format = get_commit_format(arg+8);
 			verbose_header = 1;
-			pretty_print = 1;
 			hdr_termination = '\n';
 			prefix = "commit ";
 			continue;