X-Git-Url: https://diplodocus.org/git/nmh/blobdiff_plain/23f854c962a161cc8ed982b23183600df376e818..e25b4ce52c29f7458cd203cc70f73e1a6a241ede:/sbr/utils.c

diff --git a/sbr/utils.c b/sbr/utils.c
index c25e02d4..8741b208 100644
--- a/sbr/utils.c
+++ b/sbr/utils.c
@@ -13,6 +13,9 @@
 #include <h/utils.h>
 #include <stdlib.h>
 
+/*
+ * Safely call malloc
+ */
 void *
 mh_xmalloc(size_t size)
 {
@@ -28,6 +31,9 @@ mh_xmalloc(size_t size)
     return memory;
 }
 
+/*
+ * Safely call realloc
+ */
 void *
 mh_xrealloc(void *ptr, size_t size)
 {
@@ -42,6 +48,11 @@ mh_xrealloc(void *ptr, size_t size)
 
     return memory;
 }
+
+/*
+ * Return the present working directory, if the current directory does not
+ * exist, or is too long, make / the pwd.
+ */
 char *
 pwd(void)
 {
@@ -63,3 +74,40 @@ pwd(void)
 
     return curwd;
 }
+
+/*
+ * add   -- If "s1" is NULL, this routine just creates a
+ *       -- copy of "s2" into newly malloc'ed memory.
+ *       --
+ *       -- If "s1" is not NULL, then copy the concatenation
+ *       -- of "s1" and "s2" (note the order) into newly
+ *       -- malloc'ed memory.  Then free "s1".
+ */
+char *
+add (char *s2, char *s1)
+{
+    char *cp;
+    size_t len1 = 0, len2 = 0;
+
+    if (s1)
+        len1 = strlen (s1);
+    if (s2)
+        len2 = strlen (s2);
+
+    cp = mh_xmalloc (len1 + len2 + 1);
+
+    /* Copy s1 and free it */
+    if (s1) {
+        memcpy (cp, s1, len1);
+        free (s1);
+    }
+
+    /* Copy s2 */
+    if (s2)
+        memcpy (cp + len1, s2, len2);
+
+    /* Now NULL terminate the string */
+    cp[len1 + len2] = '\0';
+
+    return cp;
+}