1 files changed, 122 insertions, 0 deletions
diff --git a/include/string.h b/include/string.h
new file mode 100644
index 0000000..4d32f57
--- /dev/null
+++ b/include/string.h
@@ -0,0 +1,122 @@
+/**
+ * @file string.h
+ *
+ * @author Freya Murphy <freya@freyacat.org>
+ *
+ * String libaray functions
+ */
+
+#ifndef _STRING_H
+#define _STRING_H
+
+#include <stddef.h>
+
+/**
+ * Compare the first n bytes (interpreted as unsigned char) of the memory areas s1 and s2
+ * @param s1 - the first memory area
+ * @param s2 - the second memory area
+ * @param n - the byte count
+ * @returns an interger less than, equal to, or greater than 0 if the first n bytes
+ * of s1 are less than, equal to, or greater than s2.
+ */
+extern int memcmp(const void *restrict s1, const void *restrict s2, size_t n);
+
+/**
+ * Copy the first n bytes from memory area src to memory area dest. The memory
+ * areas must not overlap.
+ * @param dest - the destination
+ * @param src - the source
+ * @param n - the byte count
+ * @returns a pointer to dest
+ */
+extern void *memcpy(void *restrict dest, const void *restrict src, size_t n);
+
+/**
+ * Copy the first n bytes from memory area src to memory area dest. The memory
+ * areas may overlap; memmove behaves as though the bytes are first copied to a
+ * temporary array.
+ * @param dest - the destination
+ * @param src - the source
+ * @param n - the byte count
+ * @returns a pointer to dest
+ */
+extern void *memmove(void *restrict dest, const void *restrict src, size_t n);
+
+/**
+ * Fill the first n bytes of the memory region dest with the constant byte c.
+ * @param dest - the destination
+ * @param c - the byte to write
+ * @param n - the byte count
+ * @returns a pointer to dest
+ */
+extern void *memset(void *restrict dest, int c, size_t n);
+
+/**
+ * Calculates the length of the string pointed to by str, excluding
+ * the terminating null byte
+ * @param str - the string pointer
+ * @returns the length of the string in bytes
+ */
+extern size_t strlen(const char *str);
+
+/**
+ * Compare null terminated string s1 and s2. The comparison is done using
+ * unsigned characters.
+ * @param s1 - a pointer to the first string
+ * @param s2 - a pointer to the second string
+ * @returns an interger less than, equal to, or greater than 0 if s1 compares less
+ * than, equal to, or greater than s2
+ */
+extern int strcmp(const char *restrict s1, const char *restrict s2, size_t n);
+
+/**
+ * Compare at most the first n bytes of the strings s1 and s2. The comparison is
+ * done using unsigned characters.
+ * @param s1 - a pointer to the first string
+ * @param s2 - a pointer to the second string
+ * @param n - the maximum number of bytes
+ * @returns an interger less than, equal to, or greater than 0 if s1 compares less
+ * than, equal to, or greater than s2
+ */
+extern int strncmp(const char *restrict s1, const char *restrict s2, size_t n);
+
+/**
+ * Copies the string pointed to by src into the buffer pointer to by dest.
+ * The dest buffer must be long enough to hold src.
+ * @param dest - the destination
+ * @param src - the source
+ * @returns a pointer to dest
+ */
+extern char *strcpy(char *restrict dest, const char *restrict src);
+
+/**
+ * Copies the string pointed to by src into the buffer pointer to by dest.
+ * The dest buffer must be long enough to hold src or size n.
+ * @param dest - the destination
+ * @param src - the source
+ * @param n - the maximum number of bytes
+ * @returns a pointer to dest
+ */
+extern char *strncpy(char *restrict dest, const char *restrict src, size_t n);
+
+/**
+ * Copies the string pointed to by src into the buffer pointed to by dest.
+ * The dest buffer must be long enough to hold src.
+ * @param dest - the destination
+ * @param src - the source
+ * @param n - the maximum number of bytes
+ * @returns a pointer to the terminating null byte
+ */
+extern char *stpcpy(char *restrict dest, const char *restrict src);
+
+/**
+ * Copies the string pointed to by src into the buffer pointed to by dest.
+ * The dest buffer must be long enough to hold src or size n.
+ * @param dest - the destination
+ * @param src - the source
+ * @param n - the maximum number of bytes
+ * @returns a pointer to the byte after the last character copied
+ */
+extern char *stpncpy(char *restrict dest, const char *restrict src, size_t n);
+
+#endif /* string.h */