In the locking discussion of mh-folders(5), discourage direct

[nmh] / sbr / utils.c

diff --git a/sbr/utils.c b/sbr/utils.c
index a279a327d16f70cf6b60e3500419d77362c4af97..262e5767837b440464334c9bd672a81eb2c24d5c 100644 (file)
--- a/sbr/utils.c
+++ b/sbr/utils.c
@@ -94,7 +94,7 @@ pwd(void)
  *       -- malloc'ed memory.  Then free "s1".
  */
 char *
-add (char *s2, char *s1)
+add (const char *s2, char *s1)
 {
     char *cp;
     size_t len1 = 0, len2 = 0;
@@ -127,7 +127,7 @@ add (char *s2, char *s1)
  *     Append an item to a comma separated list
  */
 char *
-addlist (char *list, char *item)
+addlist (char *list, const char *item)
 {
     if (list)
        list = add (", ", list);
@@ -139,7 +139,7 @@ addlist (char *list, char *item)
  * folder_exists
  *      Check to see if a folder exists.
  */
-int folder_exists(char *folder)
+int folder_exists(const char *folder)
 {
     struct stat st;
     int exists = 0;
@@ -241,3 +241,65 @@ open_form(char **form, char *def)
        }
        return in;
 }
+
+
+/*
+ * Finds first occurrence of str in buf.  buf is not a C string but a
+ * byte array of length buflen.  str is a null-terminated C string.
+ * find_str() does not modify buf but passes back a non-const char *
+ * pointer so that the caller can modify it.
+ */
+char *
+find_str (const char buf[], size_t buflen, const char *str) {
+    const size_t len = strlen (str);
+    size_t i;
+
+    for (i = 0; i + len <= buflen; ++i, ++buf) {
+        if (! memcmp (buf, str, len)) return (char *) buf;
+    }
+
+    return NULL;
+}
+
+
+/*
+ * Finds last occurrence of str in buf.  buf is not a C string but a
+ * byte array of length buflen.  str is a null-terminated C string.
+ * find_str() does not modify buf but passes back a non-const char *
+ * pointer so that the caller can modify it.
+ */
+char *
+rfind_str (const char buf[], size_t buflen, const char *str) {
+    const size_t len = strlen (str);
+    size_t i;
+
+    for (i = 0, buf += buflen - len; i + len <= buflen; ++i, --buf) {
+        if (! memcmp (buf, str, len)) return (char *) buf;
+    }
+
+    return NULL;
+}
+
+
+/* POSIX doesn't have strcasestr() so emulate it. */
+char *
+nmh_strcasestr (const char *s1, const char *s2) {
+    const size_t len = strlen (s2);
+
+    if (isupper ((unsigned char) s2[0])  ||  islower ((unsigned char)s2[0])) {
+        char first[3];
+        first[0] = (char) toupper ((unsigned char) s2[0]);
+        first[1] = (char) tolower ((unsigned char) s2[0]);
+        first[2] = '\0';
+
+        for (s1 = strpbrk (s1, first); s1; s1 = strpbrk (++s1, first)) {
+            if (! strncasecmp (s1, s2, len)) return (char *) s1;
+        }
+    } else {
+        for (s1 = strchr (s1, s2[0]); s1; s1 = strchr (++s1, s2[0])) {
+            if (! strncasecmp (s1, s2, len)) return (char *) s1;
+        }
+    }
+
+    return NULL;
+}