2 files changed, 29 insertions, 0 deletions
diff --git a/eprintf.c b/eprintf.c
index 9f4aa11..d1cde98 100644
--- a/eprintf.c
+++ b/eprintf.c
@@ -9,6 +9,7 @@
 #include "eprintf.h"
 
 static char *pname;
+static int debug = 0;
 
 // doprintf: print error message
 __attribute__((format(printf, 1, 0)))
@@ -48,6 +49,25 @@ void weprintf(const char *fmt, ...)
 	va_end(va);
 }
 
+// deprintf: print debug message if debugging is enabled
+void deprintf(const char *fmt, ...)
+{
+	va_list va;
+
+	assert(fmt != NULL);
+
+	if (!debug)
+		return;
+
+	if (pname != NULL)
+		fprintf(stderr, "%s: ", pname);
+
+	fputs("debug: ", stderr);
+	va_start(va, fmt);
+	vfprintf(stderr, fmt, va);
+	va_end(va);
+}
+
 // estrdup: attempt to strdup a string or exit on error
 char *estrdup(const char *s)
 {
@@ -115,3 +135,9 @@ void setprogname(const char *s)
 
 	pname = estrdup(s);
 }
+
+// setdebug: set debug
+void setdebug(int d)
+{
+	debug = d;
+}
diff --git a/eprintf.h b/eprintf.h
index 0bd662b..1afc4a6 100644
--- a/eprintf.h
+++ b/eprintf.h
@@ -7,10 +7,13 @@ noreturn void eprintf(const char *fmt, ...)
 	__attribute__((format(printf, 1, 2)));
 void weprintf(const char *fmt, ...)
 	__attribute__((format(printf, 1, 2)));
+void deprintf(const char *fmt, ...)
+	__attribute__((format(printf, 1, 2)));
 char *estrdup(const char *str);
 void *emalloc(size_t size);
 void *ecalloc(size_t nmemb, size_t size);
 void *erealloc(void *p, size_t size);
 void setprogname(const char *name);
+void setdebug(int d);
 
 #endif // !EPRINTF_EPRINTF_H