From 2c9c526255ada53d1b75d856e6554e7508740411 Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Tue, 26 Jul 2016 03:15:13 -0300
Subject: [PATCH] sch2fig/: new option -Dvar=value to set <var> in template

---
 sch2fig/fig.c  | 31 +++++++++++++++++++++++++++++--
 sch2fig/fig.h  |  2 +-
 sch2fig/main.c | 16 +++++++++++++---
 3 files changed, 43 insertions(+), 6 deletions(-)

diff --git a/sch2fig/fig.c b/sch2fig/fig.c
index 90defc8..595bcb6 100644
--- a/sch2fig/fig.c
+++ b/sch2fig/fig.c
@@ -420,7 +420,32 @@ static void fig_header(void)
 }
 
 
-void fig_init(const char *template)
+static bool apply_vars(char *buf, int n_vars, const char **vars)
+{
+	char *p;
+	const char **var, *eq;
+	int var_len, value_len;
+
+	p = strchr(buf, '<');
+	if (!p)
+		return 0;
+	for (var = vars; var != vars + n_vars; var++) {
+		eq = strchr(*var, '=');
+		assert(eq);
+		var_len = eq - *var;
+		if (strncmp(p + 1, *var, var_len))
+			continue;
+		value_len = strlen(eq + 1);
+		memmove(p + value_len, p + var_len + 2,
+		    strlen(p + var_len + 2) + 1);
+		memcpy(p, eq + 1, value_len);
+		return 1;
+	}
+	return 0;
+}
+
+
+void fig_init(const char *template, int n_vars, const char **vars)
 {
 	FILE *file;
 	char buf[1000];
@@ -435,7 +460,9 @@ void fig_init(const char *template)
 		perror(template);
 		exit(1);
 	}
-	while (fgets(buf, sizeof(buf), file))
+	while (fgets(buf, sizeof(buf), file)) {
+		while (apply_vars(buf, n_vars, vars));
 		printf("%s", buf);
+	}
 	fclose(file);
 }
diff --git a/sch2fig/fig.h b/sch2fig/fig.h
index c90f27f..528d851 100644
--- a/sch2fig/fig.h
+++ b/sch2fig/fig.h
@@ -53,6 +53,6 @@ void fig_text(int x, int y, const char *s, unsigned size,
 
 /* inititalization */
 
-void fig_init(const char *template);
+void fig_init(const char *template, int n_vars, const char **vars);
 
 #endif /* !FIG_H */
diff --git a/sch2fig/main.c b/sch2fig/main.c
index 49c7b2c..d0ef7de 100644
--- a/sch2fig/main.c
+++ b/sch2fig/main.c
@@ -59,7 +59,8 @@ static void read_file(const char *name, void *ctx,
 static void usage(const char *name)
 {
 	fprintf(stderr,
-	    "usage: %s [-t template.fig] [file.lib ...] file.sch\n", name);
+"usage: %s [-t template.fig] [-Dvar=value ...] [file.lib ...] file.sch\n",
+    name);
 	exit(1);
 }
 
@@ -69,12 +70,21 @@ int main(int argc, char **argv)
 	const char *template = NULL;
 	char c;
 	int arg;
+	int n_vars = 0;
+	const char **vars = NULL;
 
-	while ((c = getopt(argc, argv, "t:")) != EOF)
+	while ((c = getopt(argc, argv, "t:D:")) != EOF)
 		switch (c) {
 		case 't':
 			template = optarg;
 			break;
+		case 'D':
+			if (!strchr(optarg, '='))
+				usage(*argv);
+			n_vars++;
+			vars = realloc(vars, sizeof(const char *) * n_vars);
+			vars[n_vars - 1] = optarg;
+			break;
 		default:
 			usage(*argv);
 		}
@@ -82,7 +92,7 @@ int main(int argc, char **argv)
 	if (argc - optind < 1)
 		usage(*argv);
 
-	fig_init(template);
+	fig_init(template, n_vars, vars);
 	for (arg = optind; arg != argc; arg++) {
 		if (arg == argc - 1) {
 			struct sch_ctx ctx;