fixed grep

libmu/replace.c

@@ -0,0 +1,30 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+
+char *mu_replace(const char *prog_name, const char *src, const char *str, const char *fmt) {
+	size_t src_len = strlen(src);
+	size_t str_len = strlen(str);
+	size_t fmt_len = strlen(fmt);
+
+	char *buf = malloc(src_len - fmt_len + str_len + 1);
+	if (buf == NULL) {
+		if (prog_name)
+			fprintf(stderr, "%s: malloc failed: %s\n", prog_name, strerror(errno));
+
+		return NULL;
+	}
+
+	strcpy(buf, src);
+
+	/* REPLACE */
+	char *ptr = strstr(buf, fmt);
+	if (ptr == NULL)
+		return NULL;
+
+	memmove(ptr + str_len, ptr + fmt_len, strlen(ptr + fmt_len) + 1);
+	strncpy(ptr, str, str_len);
+	return buf;
+}