Add -H

4 files changed, 67 insertions, 9 deletions

diff --git a/src/globals.h b/src/globals.h
index 1285db3..f0ed91b 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -15,15 +15,22 @@ typedef struct {
 #endif
 } op_t;
 
+enum {
+	HDR_NEVER,
+	HDR_MULTI,
+	HDR_ALWAYS,
+};
+
 typedef struct {
-	bool b : 1;
-	bool c : 1;
-	bool i : 1;
-	bool l : 1;
-	bool p : 1;
-	bool s : 1;
-	bool U : 1;
-	bool z : 1;
+	bool     b : 1;
+	bool     c : 1;
+	unsigned H : 2;
+	bool     i : 1;
+	bool     l : 1;
+	bool     p : 1;
+	bool     s : 1;
+	bool     U : 1;
+	bool     z : 1;
 
 #if !GIT_GRAB
 	bool do_header : 1;
diff --git a/src/main.c b/src/main.c
index a71b554..a386362 100644
--- a/src/main.c
+++ b/src/main.c
@@ -69,6 +69,7 @@ main(int argc, char **argv)
 		{'b', U8C("byte-offset"),   CLI_NONE},
 		{'c', U8C("color"),         CLI_NONE},
 		{'h', U8C("help"),          CLI_NONE},
+		{'H', U8C("header-line"),   CLI_REQ},
 		{'i', U8C("ignore-case"),   CLI_NONE},
 		{'l', U8C("literal"),       CLI_NONE},
 		{'L', U8C("line-position"), CLI_NONE},
@@ -95,6 +96,26 @@ main(int argc, char **argv)
 		case 'h':
 			execlp("man", "man", "1", mlib_progname(), nullptr);
 			err("execlp: man 1 %s:", mlib_progname());
+		case 'H':
+			if (ucseq(parser.optarg, U8("never")))
+				flags.H = HDR_NEVER;
+			else if (ucseq(parser.optarg, U8("multi")))
+				flags.H = HDR_MULTI;
+			else if (ucseq(parser.optarg, U8("always")))
+				flags.H = HDR_ALWAYS;
+			else if (parser.optarg.len == 0) {
+				warn("empty value given for option %s--header-line%s",
+				     lquot, rquot);
+				goto usage;
+			} else {
+				warn("unknown value %s%.*s%s for option %s--header-line%s",
+				     lquot, SV_PRI_ARGS(parser.optarg), rquot, lquot, rquot);
+				goto usage;
+			}
+#if !GIT_GRAB
+			flags.do_header = true;
+#endif
+			break;
 		case 'i':
 			flags.i = true;
 			break;
@@ -130,7 +151,7 @@ main(int argc, char **argv)
 
 	if (argc == 0) {
 	usage:
-		usage("[-bcilLpsUz] pattern [file ...]", "-h");
+		usage("[-H never|multi|always] [-bcilLpsUz] pattern [file ...]", "-h");
 		exit(EXIT_FATAL);
 	}
 
diff --git a/src/work.c b/src/work.c
index bf66fdb..c8a3e21 100644
--- a/src/work.c
+++ b/src/work.c
@@ -18,6 +18,7 @@
 #include <macros.h>
 #include <mbstring.h>
 #include <pcre2.h>
+#include <rune.h>
 #include <unicode/string.h>
 
 #include "exitcodes.h"
@@ -39,6 +40,7 @@ typedef struct {
 } pos_state_t;
 
 static void compute_pos(const char8_t *p, pos_state_t *ps);
+static bool has_lbrk_p(u8view_t sv);
 static bool islbrk(u8view_t g);
 static int svposcmp(const void *a, const void *b);
 static void write_match_to_buffer(u8view_t sv, u8view_t *hl);
@@ -375,6 +377,15 @@ write_match_to_buffer(u8view_t sv, u8view_t *hl)
 		array_extend_sv(buf, COL_SE);
 		array_push(buf, sep);
 		array_extend_sv(buf, COL_RS);
+
+		switch (flags.H) {
+		case HDR_ALWAYS:
+			array_push(buf, '\n');
+			break;
+		case HDR_MULTI:
+			if (has_lbrk_p(sv))
+				array_push(buf, '\n');
+		}
 	}
 
 #pragma GCC diagnostic pop
@@ -453,6 +464,25 @@ compute_pos(const char8_t *p, pos_state_t *ps)
 }
 
 bool
+has_lbrk_p(u8view_t sv)
+{
+	rune ch;
+	while (ucsnext(&ch, &sv) != 0) {
+		switch (ch) {
+		case '\r':     /* Not *really* a newline, but it can mess with output */
+		case '\n':
+		case '\v':
+		case '\f':
+		case 0x85:
+		case RUNE_C(0x2028):
+		case RUNE_C(0x2029):
+			return true;
+		}
+	}
+	return false;
+}
+
+bool
 islbrk(u8view_t g)
 {
 	return ucseq(g, U8("\n"))
diff --git a/vendor/mlib b/vendor/mlib
-Subproject 045f4bb5b1767140c4f6cfe2d2002553925c420
+Subproject 192cabe89d0baa1b2f32434c830b40e82f5a785