utils: add decolor() to remove ANSI escape sequence from string

include/villas/utils.h

@@ -263,6 +263,9 @@ pid_t spawn(const char *name, char *const argv[]);
 /** Determines the string length as printed on the screen (ignores escable sequences). */
 size_t strlenp(const char *str);
 
+/** Remove ANSI control sequences for colored output. */
+char * decolor(char *str);
+
 
 #ifdef __cplusplus
 }

lib/utils.c

@@ -384,3 +384,36 @@ size_t strlenp(const char *str)
 
 	return sz;
 }
+
+char * decolor(char *str)
+{
+	char *p, *q;
+	bool inseq = false;
+
+	for (p = q = str; *p; p++) {
+		switch (*p) {
+			case 0x1b:
+				if (*(++p) == '[') {
+					inseq = true;
+					continue;
+				}
+				break;
+
+			case 'm':
+				if (inseq) {
+					inseq = false;
+					continue;
+				}
+				break;
+		}
+
+		if (!inseq) {
+			*q = *p;
+			q++;
+		}
+	}
+
+	*q = '\0';
+
+	return str;
+}

tests/unit/utils.c

@@ -184,3 +184,13 @@ Test(utils, sha1sum)
 
 	fclose(f);
 }
+
+Test(utils, decolor)
+{
+	char str[] = "This " CLR_RED("is") " a " CLR_BLU("colored") " " CLR_BLD("text!");
+	char expect[] = "This is a colored text!";
+
+	decolor(str);
+
+	cr_assert_str_eq(str, expect);
+}