Changeset ea4910b in mainline for uspace/lib/c/generic/string.c

Timestamp:

2018-11-30T10:04:57Z (5 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

26f5bdf, 4aba581

Parents:

c483fca

git-author:

Jiri Svoboda <jiri@…> (2018-11-29 18:02:24)

git-committer:

Jiri Svoboda <jiri@…> (2018-11-30 10:04:57)

Message:

strdup(), strndup(), strnlen() are commonly used extensions so move them to libc (native ports can use these).

File:

• uspace/lib/c/generic/string.c (modified) (2 diffs)

uspace/lib/c/generic/string.c

@@ -33 +33 @@
  */
 
-/* Prevent an error from being generated */
-#undef _HELENOS_SOURCE
+#include <errno.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <str_error.h>
 #include <string.h>
-#define _HELENOS_SOURCE
-
-#include <stddef.h>
-#include <str_error.h>
 
 /** Copy string.
@@ -504 +502 @@
 }
 
+/** Return number of characters in string with length limit.
+ *
+ * @param s String
+ * @param maxlen Maximum number of characters to read
+ * @return Number of characters preceding the null character, at most @a maxlen.
+ */
+size_t strnlen(const char *s, size_t maxlen)
+{
+        size_t n;
+
+        n = 0;
+        while (n < maxlen && *s != '\0') {
+                ++s;
+                ++n;
+        }
+
+        return n;
+}
+
+/** Allocate a new duplicate of string.
+ *
+ * @param s String to duplicate
+ * @return New string or @c NULL on failure (in which case @c errno is set
+ *         to ENOMEM).
+ */
+char *strdup(const char *s)
+{
+        size_t sz;
+        char *dup;
+
+        sz = strlen(s);
+        dup = malloc(sz + 1);
+        if (dup == NULL) {
+                errno = ENOMEM;
+                return NULL;
+        }
+
+        strcpy(dup, s);
+        return dup;
+}
+
+/** Allocate a new duplicate of string with length limit.
+ *
+ * Creates a new duplicate of @a s. If @a s is longer than @a n characters,
+ * only @a n characters are copied and a null character is appended.
+ *
+ * @param s String to duplicate
+ * @param n Maximum number of characters to copy
+ * @return New string or @c NULL on failure (in which case @c errno is set
+ *         to ENOMEM).
+ */
+char *strndup(const char *s, size_t n)
+{
+        size_t sz;
+        char *dup;
+
+        sz = strnlen(s, n);
+        dup = malloc(sz + 1);
+        if (dup == NULL) {
+                errno = ENOMEM;
+                return NULL;
+        }
+
+        strcpy(dup, s);
+        return dup;
+}
+
 /** @}
  */