X-Git-Url: https://diplodocus.org/git/nmh/blobdiff_plain/8a4d2247f60879752e29203e7a01c49910ed199c..c3ba36f92bcbf44e071961f3d0bb5e6ddab317d6:/sbr/utils.c?ds=sidebyside

diff --git a/sbr/utils.c b/sbr/utils.c
index b7580252..78ec2da9 100644
--- a/sbr/utils.c
+++ b/sbr/utils.c
@@ -179,22 +179,10 @@ addlist (char *list, const char *item)
 int folder_exists(const char *folder)
 {
     struct stat st;
-    int exists = 0;
 
-    if (stat (folder, &st) == -1) {
-        /* The folder either doesn't exist, or we hit an error.  Either way
-         * return a failure.
-         */
-        exists = 0;
-    } else {
-        /* We can see a folder with the right name */
-        exists = 1;
-    }
-
-    return exists;
+    return stat(folder, &st) != -1;
 }
 
-
 /*
  * create_folder
  *      Check to see if a folder exists, if not, prompt the user to create
@@ -358,9 +346,58 @@ nmh_strcasestr (const char *s1, const char *s2) {
 }
 
 
-/* EndsWithC returns true if non-NULL string s ends with a c before the
+/* truncpy copies at most size - 1 chars from non-NULL src to non-NULL,
+ * non-overlapping, dst, and ensures dst is NUL terminated.  If size is
+ * zero then it aborts as dst cannot be NUL terminated.
+ *
+ * It's to be used when truncation is intended and correct, e.g.
+ * reporting a possibly very long external string back to the user.  One
+ * of its advantages over strncpy(3) is it doesn't pad in the common
+ * case of no truncation. */
+void trunccpy(char *dst, const char *src, size_t size)
+{
+    if (!size) {
+        advise(NULL, "trunccpy: zero-length destination: \"%.20s\"",
+            src ? src : "null");
+        abort();
+    }
+
+    if (strnlen(src, size) < size) {
+        strcpy(dst, src);
+    } else {
+        memcpy(dst, src, size - 1);
+        dst[size - 1] = '\0';
+    }
+}
+
+
+/* HasPrefix returns true if non-NULL s starts with non-NULL prefix. */
+bool HasPrefix(const char *s, const char *prefix)
+{
+    while (*s && *s == *prefix) {
+        s++;
+        prefix++;
+    }
+
+    return *prefix == '\0';
+}
+
+
+/* HasSuffix returns true if non-NULL s ends with non-NULL suffix. */
+bool HasSuffix(const char *s, const char *suffix)
+{
+    size_t ls, lsuf;
+
+    ls = strlen(s);
+    lsuf = strlen(suffix);
+
+    return lsuf <= ls && !strcmp(s + ls - lsuf, suffix);
+}
+
+
+/* HasSuffixC returns true if non-NULL string s ends with a c before the
  * terminating NUL. */
-bool EndsWithC(char *s, int c)
+bool HasSuffixC(const char *s, int c)
 {
     return *s && s[strlen(s) - 1] == c;
 }
@@ -490,7 +527,7 @@ nmh_version_changed (int older) {
            break for versions with multiple decimal points, etc. */
         const float current_version = strtof (VERSION, NULL);
         const float old_version =
-            context_version  &&  strncmp (context_version, "nmh-", 4) == 0
+            context_version  &&  HasPrefix(context_version, "nmh-")
             ?  strtof (context_version + 4, NULL)
             :  99999999;