handle -x with regex

1 files changed, 14 insertions, 3 deletions

diff --git a/grep.c b/grep.c
index 71a28c2..b508c77 100644
--- a/grep.c
+++ b/grep.c
@@ -48,7 +48,6 @@ static int grep_inverse = 0;
 static int grep_silent = 0;
 static int grep_exact = 0;
 
-/* TODO: handle -x */
 static int grep_match_re(struct grep_list *head, const char *buf)
 {
 	for (struct grep_list *c = head; c != NULL; c = c->next) {
@@ -176,8 +175,14 @@ static struct grep_list * grep_add_list(struct grep_list *head, char *s)
 			tmp->next = node;
 		}
 
-		node->string = strdup(pattern);
-		node->len = strlen(node->string);
+		/* reserve space for adding ^ and $ if needed */
+		node->len = strlen(pattern);
+		node->string = malloc(node->len + 3);
+		if (node->string == NULL) {
+			perror("grep");
+			exit(2);
+		}
+		strcpy(node->string, pattern);
 
 		pattern = strtok(NULL, "\n");
 	}
@@ -283,6 +288,12 @@ int main(int argc, char *argv[])
 
 	if (type != FIXED) {
 		for (struct grep_list *c = head; c != NULL; c = c->next) {
+			if (grep_exact) {
+				memmove(c->string + 1, c->string, c->len);
+				c->string[0] = '^';
+				c->string[c->len + 1] = '$';
+			}
+
 			int e = regcomp(&(c->re), c->string, flags);
 			if (e == 0) {
 				free(c->string);