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-rw-r--r--src/string/strspn.c96
1 files changed, 96 insertions, 0 deletions
diff --git a/src/string/strspn.c b/src/string/strspn.c
new file mode 100644
index 0000000..cf82529
--- /dev/null
+++ b/src/string/strspn.c
@@ -0,0 +1,96 @@
+/**
+ * slibc — Yet another C library
+ * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <string.h>
+#include <stddef.h>
+
+
+
+/**
+ * Returns length of the initial substring
+ * that consists entirely of a set of specified
+ * bytes.
+ *
+ * @param string The string.
+ * @param skipset Bytes allowed in the substring.
+ * @return The length of the substring.
+ */
+size_t strspn(const char* string, const char* skipset)
+{
+ char set[256];
+ char c;
+ const char* s = string;
+ memset(set, 0, 256);
+ while ((c = *skipset++))
+ set[(size_t)c] = 1;
+ while ((c = *s++))
+ if (set[(size_t)c])
+ break;
+ return (size_t)(s - 1 - string);
+}
+
+
+/**
+ * Returns length of the initial substring
+ * that consists entirely of the complement
+ * of a set of specified bytes.
+ *
+ * @param string The string.
+ * @param stopset Bytes disallowed in the substring.
+ * @return The length of the substring.
+ */
+size_t strcspn(const char* string, const char* stopset)
+{
+ char set[256];
+ char c;
+ const char* s = string;
+ memset(set, 0, 256);
+ while ((c = *skipset++))
+ set[(size_t)c] = 1;
+ while ((c = *s++))
+ if (!set[(size_t)c])
+ break;
+ return (size_t)(s - 1 - string);
+}
+
+
+/**
+ * This function works like `strcspn`,
+ * except it returns the pointer to the
+ * location of the first found non-matching
+ * byte.
+ *
+ * @param string The string.
+ * @param stopset Bytes disallowed in the substring.
+ * @return A pointer to the first occurrence in
+ * `string` of a byte found in `stopset`.
+ * `NULL` is returned if none is found.
+ */
+char* stpbrk(const char* string, const char* stopset)
+{
+ char set[256];
+ char c;
+ const char* s = string;
+ memset(set, 0, 256);
+ while ((c = *skipset++))
+ set[(size_t)c] = 1;
+ while ((c = *s++))
+ if (!set[(size_t)c])
+ break;
+ return c ? (s - 1) : NULL;
+}
+