dev(sell): add simple libc and implement shell

please see the log for detail.

1 files changed, 70 insertions, 0 deletions

diff --git a/include/ulib/string.h b/include/ulib/string.h
new file mode 100644
index 0000000..6e87157
--- /dev/null
+++ b/include/ulib/string.h
@@ -0,0 +1,70 @@
+#ifndef _STRING_H
+#define _STRING_H
+
+#include "ulib/types.h"
+#include "ulib/errno.h"
+
+#ifndef _SIZE_T
+#define _SIZE_T
+typedef unsigned long long size_t;
+#endif
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+    /* Memory Manipulation*/
+    void *memcpy(void *dest, const void *src, size_t n);
+
+    void *memmove(void *dest, const void *src, size_t n);
+
+    void *memset(void *dest, int c, size_t n);
+
+    int memcmp(const void *s1, const void *s2, size_t n);
+
+    void *memchr(const void *s, int c, size_t n);
+
+    /* String Manipulation */
+
+    size_t strlen(const char *s);
+
+    char *strcpy(char *dest, const char *src);
+
+    char *strncpy(char *dest, const char *src, size_t n);
+
+    char *strcat(char *dest, const char *src);
+
+    char *strncat(char *dest, const char *src, size_t n);
+
+    int strcmp(const char *s1, const char *s2);
+
+    int strncmp(const char *s1, const char *s2, size_t n);
+
+    char *strchr(const char *s, int c);
+
+    char *strrchr(const char *s, int c);
+
+    char *strstr(const char *haystack, const char *needle);
+
+    char *strdup(const char *s);
+
+    size_t strlcpy(char *dest, const char *src, size_t size);
+
+    size_t strlcat(char *dest, const char *src, size_t size);
+
+    size_t strspn(const char *s, const char *accept);
+
+    size_t strcspn(const char *s, const char *reject);
+
+    char *strpbrk(const char *s, const char *accept);
+
+    char *strtok(char *str, const char *delim);
+
+    char *strerror(int errnum);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _STRING_H */
\ No newline at end of file