Replaced strncpy with hand-written function suggested by NRK

1 files changed, 23 insertions, 7 deletions

diff --git a/sdep.c b/sdep.c
index 9279c39..fe67b95 100644
--- a/sdep.c
+++ b/sdep.c
@@ -56,6 +56,7 @@ static char *format_line(Event, Options, char *);
 static int is_space(char);
 static void read_input(Options, EventList *);
 static Options read_op(int, char *[]);
+static void str_copy(char *, char *, int);
 static char *str_trim(char *);
 static void write_output(Options, Event *, int);
 
@@ -63,12 +64,12 @@ static void write_output(Options, Event *, int);
 static void
 add_event(struct tm t, char *text, EventList *evlist)
 {
-        int l = strlen(text)+1;
+        size_t l = strlen(text)+1;
         EventNode *next = malloc(sizeof(EventNode));
 
         next->ev.time = t;
         next->ev.text = malloc(l);
-        strncpy(next->ev.text, text, l);
+        str_copy(next->ev.text, text, l);
         next->ev.text = str_trim(next->ev.text);
         next->next = NULL;
 
@@ -149,9 +150,13 @@ events_in_range(EventList *evlist, Options op, Event *sel)
 static char *
 format_line(Event ev, Options op, char *out)
 {
+        size_t l;
+
         strftime(out, MAXLEN, op.format_out, &ev.time);
-        strncat(out, op.separator, MAXLEN - strlen(out));
-        strncat(out, ev.text, MAXLEN - strlen(out));
+        l = strlen(out);
+
+        str_copy(out+l, op.separator, MAXLEN - l);
+        str_copy(out+l, ev.text, MAXLEN - l);
 
         return out;
 }
@@ -183,8 +188,8 @@ read_op(int argc, char *argv[])
          * This changes the way other options are read */
         for (i = 1; i < argc; i++) {
                 if (argv[i][0] == '+') {
-                        strncpy(op.format_in,  &argv[i][1], MAXLEN);
-                        strncpy(op.format_out, &argv[i][1], MAXLEN);
+                        str_copy(op.format_in,  &argv[i][1], MAXLEN);
+                        str_copy(op.format_out, &argv[i][1], MAXLEN);
                 }
         }
 
@@ -196,7 +201,7 @@ read_op(int argc, char *argv[])
                         puts(default_format);
                         exit(0);
                 } else if (!strcmp(argv[i], "-s")) {
-                        strncpy(op.separator, argv[++i], MAXLEN);
+                        str_copy(op.separator, argv[++i], MAXLEN);
                 } else if (!strcmp(argv[i], "-f")) {
                         if (i+1 >= argc ||
                             strptime(argv[i+1], op.format_in, &op.from) == NULL)
@@ -222,6 +227,17 @@ read_op(int argc, char *argv[])
         return op;
 }
 
+/*
+ * Copy up to n characters of the string str to dst and append '\0'.
+ * Suggested by NRK.
+ */
+static void
+str_copy(char *dst, char *src, int n)
+{
+        if (memccpy(dst, src, '\0', n) == NULL)
+                dst[n-1] = '\0';
+}
+
 static char *
 str_trim(char *t)
 {