From 01e2dfc79126a7600463b4cf9fa16b4be6886cae Mon Sep 17 00:00:00 2001
From: Tiago Teles <tiago.sequeira.teles@gmail.com>
Date: Tue, 26 May 2020 19:55:55 +0100
Subject: [PATCH] -dy flag for dynamic menu updating

This patch adds a flag (`-dy`) which makes dmenu run the command given to it
whenever input is changed with the current input as the last argument and
update the option list according to the output of that command.
---
 config.def.h |  1 +
 dmenu.c      | 43 ++++++++++++++++++++++++++++++++++++-------
 2 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/config.def.h b/config.def.h
index 1edb6477..035b8777 100644
--- a/config.def.h
+++ b/config.def.h
@@ -7,6 +7,7 @@ static const char *fonts[] = {
 	"monospace:size=10"
 };
 static const char *prompt      = NULL;      /* -p  option; prompt to the left of input field */
+static const char *dynamic     = NULL;      /* -dy option; dynamic command to run on input change */
 static const char *colors[SchemeLast][2] = {
 	/*     fg         bg       */
 	[SchemeNorm] = { "#bbbbbb", "#222222" },
diff --git a/dmenu.c b/dmenu.c
index 6b8f51b5..356d4cc9 100644
--- a/dmenu.c
+++ b/dmenu.c
@@ -210,9 +210,33 @@ grabkeyboard(void)
 	die("cannot grab keyboard");
 }
 
+static void readstdin(FILE* stream);
+
+static void
+refreshoptions(){
+	int dynlen = strlen(dynamic);
+	char* cmd= malloc(dynlen + strlen(text)+2);
+	if(cmd == NULL)
+		die("malloc:");
+	sprintf(cmd,"%s %s",dynamic, text);
+	FILE *stream = popen(cmd, "r");
+	if(!stream)
+		die("popen(%s):",cmd);
+	readstdin(stream);
+	int pc = pclose(stream);
+	if(pc == -1)
+		die("pclose:");
+	free(cmd);
+	curr = sel = items;
+}
+
 static void
 match(void)
 {
+	if(dynamic && *dynamic){
+		refreshoptions();
+	}
+
 	static char **tokv = NULL;
 	static int tokn = 0;
 
@@ -234,7 +258,7 @@ match(void)
 		for (i = 0; i < tokc; i++)
 			if (!fstrstr(item->text, tokv[i]))
 				break;
-		if (i != tokc) /* not all tokens match */
+		if (i != tokc && !(dynamic && *dynamic)) /* not all tokens match */
 			continue;
 		/* exact matches go first, then prefixes, then substrings */
 		if (!tokc || !fstrncmp(text, item->text, textsize))
@@ -519,14 +543,14 @@ paste(void)
 }
 
 static void
-readstdin(void)
+readstdin(FILE* stream)
 {
 	char buf[sizeof text], *p;
 	size_t i, imax = 0, size = 0;
 	unsigned int tmpmax = 0;
 
 	/* read each line from stdin and add it to the item list */
-	for (i = 0; fgets(buf, sizeof buf, stdin); i++) {
+	for (i = 0; fgets(buf, sizeof buf, stream); i++) {
 		if (i + 1 >= size / sizeof *items)
 			if (!(items = realloc(items, (size += BUFSIZ))))
 				die("cannot realloc %u bytes:", size);
@@ -544,7 +568,8 @@ readstdin(void)
 	if (items)
 		items[i].text = NULL;
 	inputw = items ? TEXTW(items[imax].text) : 0;
-	lines = MIN(lines, i);
+	if (!dynamic || !*dynamic)
+		lines = MIN(lines, i);
 }
 
 static void
@@ -683,7 +708,7 @@ static void
 usage(void)
 {
 	fputs("usage: dmenu [-bfiv] [-l lines] [-p prompt] [-fn font] [-m monitor]\n"
-	      "             [-nb color] [-nf color] [-sb color] [-sf color] [-w windowid]\n", stderr);
+	      "             [-nb color] [-nf color] [-sb color] [-sf color] [-w windowid]\n" "[-dy command]\n", stderr);
 	exit(1);
 }
 
@@ -726,6 +751,8 @@ main(int argc, char *argv[])
 			colors[SchemeSel][ColFg] = argv[++i];
 		else if (!strcmp(argv[i], "-w"))   /* embedding window id */
 			embed = argv[++i];
+		else if (!strcmp(argv[i], "-dy"))  /* dynamic command to run */
+			dynamic = argv[++i];
 		else
 			usage();
 
@@ -754,9 +781,11 @@ main(int argc, char *argv[])
 
 	if (fast && !isatty(0)) {
 		grabkeyboard();
-		readstdin();
+		if(!(dynamic && *dynamic))
+			readstdin(stdin);
 	} else {
-		readstdin();
+		if(!(dynamic && *dynamic))
+			readstdin(stdin);
 		grabkeyboard();
 	}
 	setup();
-- 
2.26.2