diff --git a/libc/include/assert.h b/libc/include/assert.h
new file mode 100644
index 0000000..91ab8a4
--- /dev/null
+++ b/libc/include/assert.h
@@ -0,0 +1,4 @@
+#ifndef _ASSERT_H
+#define _ASSERT_H
+
+#endif
diff --git a/libc/include/aux.h b/libc/include/aux.h
index 88827ac..d450b59 100644
--- a/libc/include/aux.h
+++ b/libc/include/aux.h
@@ -1,7 +1,7 @@
 #ifndef __FENNIX_LIBC_AUX_H__
 #define __FENNIX_LIBC_AUX_H__
 
-#include <types.h>
+#include <stddef.h>
 
 #define AT_NULL 0
 #define AT_IGNORE 1
@@ -44,11 +44,26 @@
 
 typedef struct
 {
-    unsigned long a_type;
+    uint32_t a_type;
     union
     {
-        unsigned long a_val;
+        uint32_t a_val;
+    } a_un;
+} Elf32_auxv_t;
+
+typedef struct
+{
+    uint64_t a_type;
+    union
+    {
+        uint64_t a_val;
     } a_un;
 } Elf64_auxv_t;
 
+#ifdef __LP64__
+#define Elf_auxv_t Elf64_auxv_t
+#else
+#define Elf_auxv_t Elf32_auxv_t
+#endif
+
 #endif // !__FENNIX_LIBC_AUX_H__
diff --git a/libc/include/ctype.h b/libc/include/ctype.h
index 02665dc..d8925e1 100644
--- a/libc/include/ctype.h
+++ b/libc/include/ctype.h
@@ -1,4 +1,8 @@
 #ifndef _CTYPE_H
 #define _CTYPE_H
 
+int tolower(int c);
+int toupper(int c);
+int isspace(int c);
+
 #endif // !_CTYPE_H
diff --git a/libc/include/errno.h b/libc/include/errno.h
index 34e6c68..361f042 100644
--- a/libc/include/errno.h
+++ b/libc/include/errno.h
@@ -1,4 +1,42 @@
 #ifndef _ERRNO_H
 #define _ERRNO_H
 
+#define EPERM 1    /* Operation not permitted */
+#define ENOENT 2   /* No such file or directory */
+#define ESRCH 3    /* No such process */
+#define EINTR 4    /* Interrupted system call */
+#define EIO 5      /* I/O error */
+#define ENXIO 6    /* No such device or address */
+#define E2BIG 7    /* Argument list too long */
+#define ENOEXEC 8  /* Exec format error */
+#define EBADF 9    /* Bad file number */
+#define ECHILD 10  /* No child processes */
+#define EAGAIN 11  /* Try again */
+#define ENOMEM 12  /* Out of memory */
+#define EACCES 13  /* Permission denied */
+#define EFAULT 14  /* Bad address */
+#define ENOTBLK 15 /* Block device required */
+#define EBUSY 16   /* Device or resource busy */
+#define EEXIST 17  /* File exists */
+#define EXDEV 18   /* Cross-device link */
+#define ENODEV 19  /* No such device */
+#define ENOTDIR 20 /* Not a directory */
+#define EISDIR 21  /* Is a directory */
+#define EINVAL 22  /* Invalid argument */
+#define ENFILE 23  /* File table overflow */
+#define EMFILE 24  /* Too many open files */
+#define ENOTTY 25  /* Not a typewriter */
+#define ETXTBSY 26 /* Text file busy */
+#define EFBIG 27   /* File too large */
+#define ENOSPC 28  /* No space left on device */
+#define ESPIPE 29  /* Illegal seek */
+#define EROFS 30   /* Read-only file system */
+#define EMLINK 31  /* Too many links */
+#define EPIPE 32   /* Broken pipe */
+#define EDOM 33    /* Math argument out of domain of func */
+#define ERANGE 34  /* Math result not representable */
+
+extern int *__errno_location(void) __attribute__((const));
+#define errno (*__errno_location())
+
 #endif
diff --git a/libc/include/limits.h b/libc/include/limits.h
new file mode 100644
index 0000000..e259acf
--- /dev/null
+++ b/libc/include/limits.h
@@ -0,0 +1,119 @@
+#ifndef _LIMITS_H
+#define _LIMITS_H
+
+#undef CHAR_BIT
+#define CHAR_BIT __CHAR_BIT__
+
+#ifndef MB_LEN_MAX
+#define MB_LEN_MAX 1
+#endif
+
+#undef SCHAR_MIN
+#define SCHAR_MIN (-SCHAR_MAX - 1)
+#undef SCHAR_MAX
+#define SCHAR_MAX __SCHAR_MAX__
+
+#undef UCHAR_MAX
+#if __SCHAR_MAX__ == __INT_MAX__
+#define UCHAR_MAX (SCHAR_MAX * 2U + 1U)
+#else
+#define UCHAR_MAX (SCHAR_MAX * 2 + 1)
+#endif
+
+#ifdef __CHAR_UNSIGNED__
+#undef CHAR_MIN
+#if __SCHAR_MAX__ == __INT_MAX__
+#define CHAR_MIN 0U
+#else
+#define CHAR_MIN 0
+#endif
+#undef CHAR_MAX
+#define CHAR_MAX UCHAR_MAX
+#else
+#undef CHAR_MIN
+#define CHAR_MIN SCHAR_MIN
+#undef CHAR_MAX
+#define CHAR_MAX SCHAR_MAX
+#endif
+
+#undef SHRT_MIN
+#define SHRT_MIN (-SHRT_MAX - 1)
+#undef SHRT_MAX
+#define SHRT_MAX __SHRT_MAX__
+
+#undef USHRT_MAX
+#if __SHRT_MAX__ == __INT_MAX__
+#define USHRT_MAX (SHRT_MAX * 2U + 1U)
+#else
+#define USHRT_MAX (SHRT_MAX * 2 + 1)
+#endif
+
+#undef INT_MIN
+#define INT_MIN (-INT_MAX - 1)
+#undef INT_MAX
+#define INT_MAX __INT_MAX__
+
+#undef UINT_MAX
+#define UINT_MAX (INT_MAX * 2U + 1U)
+
+#undef LONG_MIN
+#define LONG_MIN (-LONG_MAX - 1L)
+#undef LONG_MAX
+#define LONG_MAX __LONG_MAX__
+
+#undef ULONG_MAX
+#define ULONG_MAX (LONG_MAX * 2UL + 1UL)
+
+#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
+#undef LLONG_MIN
+#define LLONG_MIN (-LLONG_MAX - 1LL)
+#undef LLONG_MAX
+#define LLONG_MAX __LONG_LONG_MAX__
+
+#undef ULLONG_MAX
+#define ULLONG_MAX (LLONG_MAX * 2ULL + 1ULL)
+#endif
+
+#if defined(__GNU_LIBRARY__) ? defined(__USE_GNU) : !defined(__STRICT_ANSI__)
+#undef LONG_LONG_MIN
+#define LONG_LONG_MIN (-LONG_LONG_MAX - 1LL)
+#undef LONG_LONG_MAX
+#define LONG_LONG_MAX __LONG_LONG_MAX__
+
+#undef ULONG_LONG_MAX
+#define ULONG_LONG_MAX (LONG_LONG_MAX * 2ULL + 1ULL)
+#endif
+
+#if (defined __STDC_WANT_IEC_60559_BFP_EXT__ || (defined(__STDC_VERSION__) && __STDC_VERSION__ > 201710L))
+#undef CHAR_WIDTH
+#define CHAR_WIDTH __SCHAR_WIDTH__
+#undef SCHAR_WIDTH
+#define SCHAR_WIDTH __SCHAR_WIDTH__
+#undef UCHAR_WIDTH
+#define UCHAR_WIDTH __SCHAR_WIDTH__
+#undef SHRT_WIDTH
+#define SHRT_WIDTH __SHRT_WIDTH__
+#undef USHRT_WIDTH
+#define USHRT_WIDTH __SHRT_WIDTH__
+#undef INT_WIDTH
+#define INT_WIDTH __INT_WIDTH__
+#undef UINT_WIDTH
+#define UINT_WIDTH __INT_WIDTH__
+#undef LONG_WIDTH
+#define LONG_WIDTH __LONG_WIDTH__
+#undef ULONG_WIDTH
+#define ULONG_WIDTH __LONG_WIDTH__
+#undef LLONG_WIDTH
+#define LLONG_WIDTH __LONG_LONG_WIDTH__
+#undef ULLONG_WIDTH
+#define ULLONG_WIDTH __LONG_LONG_WIDTH__
+#endif
+
+#if defined(__STDC_VERSION__) && __STDC_VERSION__ > 201710L
+#undef BOOL_MAX
+#define BOOL_MAX 1
+#undef BOOL_WIDTH
+#define BOOL_WIDTH 1
+#endif
+
+#endif // !_LIMITS_H
diff --git a/libc/include/stdio.h b/libc/include/stdio.h
index 4429148..1572138 100644
--- a/libc/include/stdio.h
+++ b/libc/include/stdio.h
@@ -5,6 +5,8 @@
 #include <stddef.h>
 
 #define SEEK_SET 0
+#define SEEK_CUR 1
+#define SEEK_END 2
 
 typedef struct
 {
@@ -31,12 +33,17 @@ extern "C"
     size_t fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream);
     void setbuf(FILE *stream, char *buf);
     int vfprintf(FILE *stream, const char *format, va_list arg);
+    int vsscanf(const char *s, const char *format, va_list arg);
+    int sscanf(const char *s, const char *format, ...);
 
-    int puts(const char *s);
+    int fputc(int c, FILE *stream);
+    int putc(int c, FILE *stream);
+    int fputs(const char *s, FILE *stream);
     int putchar(int c);
+    int puts(const char *s);
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif
\ No newline at end of file
+#endif
diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
index fb730ff..9c7589c 100644
--- a/libc/include/stdlib.h
+++ b/libc/include/stdlib.h
@@ -18,6 +18,9 @@ extern "C"
     void *realloc(void *Address, size_t Size);
     void *calloc(size_t Count, size_t Size);
     void free(void *Address);
+    int system(const char *command);
+
+    double atof(const char *nptr);
 
 #ifdef __cplusplus
 }
diff --git a/libc/include/string.h b/libc/include/string.h
index c0eafe7..715ccf5 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -8,11 +8,18 @@ extern "C"
 {
 #endif
 
-    void *memcpy(void *, const void *, size_t);
-    void *memset(void *, int, size_t);
-    char *strcpy(char *, const char *);
-    size_t strlen(const char *);
+    size_t strlen(const char *str);
+    int strcmp(const char *l, const char *r);
     int strncmp(const char *s1, const char *s2, size_t n);
+    int strcasecmp(const char *s1, const char *s2);
+    int strncasecmp(const char *string1, const char *string2, size_t count);
+    char *strstr(const char *haystack, const char *needle);
+    char *strncpy(char *destination, const char *source, unsigned long num);
+    char *strdup(const char *s);
+    char *strchr(char const *s, int c);
+    char *strrchr(char const *s, int c);
+
+    void *memmove(void *dest, const void *src, size_t n);
 
 #ifdef __cplusplus
 }
diff --git a/libc/include/sys/stat.h b/libc/include/sys/stat.h
index 98ebeed..80471f2 100644
--- a/libc/include/sys/stat.h
+++ b/libc/include/sys/stat.h
@@ -1,4 +1,18 @@
 #ifndef _SYS_STAT_H
 #define _SYS_STAT_H
 
+typedef unsigned int _dev_t;
+typedef unsigned short _ino_t;
+typedef unsigned short _mode_t;
+typedef int _off_t;
+
+#define dev_t _dev_t
+#define ino_t _ino_t
+#define mode_t _mode_t
+#define off_t _off_t
+
+int mkdir(const char *path, mode_t mode);
+int remove(const char *pathname);
+int rename(const char *oldpath, const char *newpath);
+
 #endif
diff --git a/libc/include/sys/time.h b/libc/include/sys/time.h
new file mode 100644
index 0000000..b24289f
--- /dev/null
+++ b/libc/include/sys/time.h
@@ -0,0 +1,4 @@
+#ifndef _SYS_TIME_H
+#define _SYS_TIME_H
+
+#endif
diff --git a/libc/src/Makefile b/libc/src/Makefile
index f288986..7b8f030 100644
--- a/libc/src/Makefile
+++ b/libc/src/Makefile
@@ -19,6 +19,7 @@ ASM_SOURCES = $(shell find ./ -type f -name '*.asm')
 OBJ = ${C_SOURCES:.c=.o} ${CPP_SOURCES:.cpp=.o} ${ASM_SOURCES:.asm=.o} ${S_SOURCES:.S=.o}
 
 INCLUDE = ../include
+INCLUDE2 = ../../out/system/include
 
 ifeq ($(OSARCH), amd64)
 ASM_ARCH := elf64
@@ -26,7 +27,7 @@ else ifeq ($(OSARCH), i386)
 ASM_ARCH := elf32
 endif
 
-CFLAGS := -fPIC -I$(INCLUDE)
+CFLAGS := -fPIC -I$(INCLUDE) -I$(INCLUDE2)
 
 build: $(OBJECT_NAME)
 
diff --git a/libc/src/std/ctype.c b/libc/src/std/ctype.c
new file mode 100644
index 0000000..8258be5
--- /dev/null
+++ b/libc/src/std/ctype.c
@@ -0,0 +1,27 @@
+#include <ctype.h>
+
+int tolower(int c)
+{
+    if (c >= 'A' && c <= 'Z')
+    {
+        c -= 'A';
+        c += 'a';
+    }
+
+    return c;
+}
+
+int toupper(int c)
+{
+    if (c >= 'a' && c <= 'z')
+    {
+        c -= 'a';
+        c += 'A';
+    }
+    return c;
+}
+
+int isspace(int c)
+{
+    return c == ' ' || c == '\t' || c == '\r' || c == '\n' || c == '\f' || c == '\v';
+}
diff --git a/libc/src/std/errno.c b/libc/src/std/errno.c
new file mode 100644
index 0000000..88f8478
--- /dev/null
+++ b/libc/src/std/errno.c
@@ -0,0 +1,6 @@
+#include <errno.h>
+
+int *__errno_location(void)
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/libc/src/std/io.c b/libc/src/std/io.c
index d15017a..9b769a7 100644
--- a/libc/src/std/io.c
+++ b/libc/src/std/io.c
@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <stdarg.h>
+#include <sys/syscalls.h>
 
 FILE *stdin;
 FILE *stdout;
@@ -54,17 +55,47 @@ void setbuf(FILE *stream, char *buf)
 {
 }
 
-// int vfprintf(FILE *stream, const char *format, va_list arg)
-// {
-//     return 0;
-// }
-
-int puts(const char *s)
+int vfprintf(FILE *stream, const char *format, va_list arg)
 {
     return 0;
 }
 
+int vsscanf(const char *s, const char *format, va_list arg)
+{
+}
+
+int sscanf(const char *s, const char *format, ...)
+{
+    va_list args;
+    va_start(args, format);
+    const int ret = vsscanf(s, format, args);
+    va_end(args);
+    return ret;
+}
+
+int fputc(int c, FILE *stream)
+{
+    syscall1(_Print, c);
+}
+
+int putc(int c, FILE *stream)
+{
+    syscall1(_Print, c);
+}
+
+int fputs(const char *s, FILE *stream)
+{
+    for (int i = 0; s[i] != '\0'; i++)
+        fputc(s[i], stream);
+}
+
 int putchar(int c)
 {
-    return 0;
+    syscall1(_Print, c);
+}
+
+int puts(const char *s)
+{
+    for (int i = 0; s[i] != '\0'; i++)
+        fputc(s[i], stdout);
 }
diff --git a/libc/src/std/lib.c b/libc/src/std/lib.c
index 482ec45..286a128 100644
--- a/libc/src/std/lib.c
+++ b/libc/src/std/lib.c
@@ -23,8 +23,7 @@ void exit(int status)
 
 int atoi(const char *nptr)
 {
-    // uint64_t Length = strlen((char *)nptr);
-    uint64_t Length = 0;
+    uint64_t Length = strlen((char *)nptr);
     if (nptr)
         while (nptr[Length] != '\0')
             ++Length;
@@ -62,3 +61,25 @@ void free(void *Address)
     PREFIX(free)
     (Address);
 }
+
+int system(const char *command)
+{
+    return 0;
+}
+
+double atof(const char *nptr)
+{
+    // FIXME: This is a very bad implementation of atof.
+    uint64_t Length = strlen((char *)nptr);
+    if (nptr)
+        while (nptr[Length] != '\0')
+            ++Length;
+    double OutBuffer = 0;
+    double Power = 1;
+    for (uint64_t i = Length; i > 0; --i)
+    {
+        OutBuffer += (nptr[i - 1] - 48) * Power;
+        Power *= 10;
+    }
+    return OutBuffer;
+}
diff --git a/libc/src/std/string.c b/libc/src/std/string.c
new file mode 100644
index 0000000..d3f151d
--- /dev/null
+++ b/libc/src/std/string.c
@@ -0,0 +1,142 @@
+#include <string.h>
+
+#include "../mem/liballoc_1_1.h"
+
+size_t strlen(const char *str)
+{
+    long unsigned i = 0;
+    if (str)
+        while (str[i] != '\0')
+            ++i;
+    return i;
+}
+
+int strcmp(const char *l, const char *r)
+{
+    for (; *l == *r && *l; l++, r++)
+        ;
+    return *(unsigned char *)l - *(unsigned char *)r;
+}
+
+int strncmp(const char *s1, const char *s2, size_t n)
+{
+    for (size_t i = 0; i < n; i++)
+    {
+        char c1 = s1[i], c2 = s2[i];
+        if (c1 != c2)
+            return c1 - c2;
+        if (!c1)
+            return 0;
+    }
+    return 0;
+}
+
+int strcasecmp(const char *s1, const char *s2)
+{
+    const unsigned char *p1 = (const unsigned char *)s1;
+    const unsigned char *p2 = (const unsigned char *)s2;
+    int result;
+    if (p1 == p2)
+        return 0;
+    while ((result = tolower(*p1) - tolower(*p2++)) == 0)
+        if (*p1++ == '\0')
+            break;
+    return result;
+}
+
+int strncasecmp(const char *string1, const char *string2, size_t count)
+{
+    if (count)
+    {
+        const unsigned char *s1 = (const unsigned char *)string1;
+        const unsigned char *s2 = (const unsigned char *)string2;
+        int result;
+        do
+        {
+            if ((result = tolower(*s1) - tolower(*s2++)) != 0 || !*s1++)
+                break;
+        } while (--count);
+        return result;
+    }
+    return 0;
+}
+
+char *strstr(const char *haystack, const char *needle)
+{
+    const char *a = haystack, *b = needle;
+    while (1)
+    {
+        if (!*b)
+            return (char *)haystack;
+        if (!*a)
+            return NULL;
+        if (*a++ != *b++)
+        {
+            a = ++haystack;
+            b = needle;
+        }
+    }
+}
+
+char *strncpy(char *destination, const char *source, unsigned long num)
+{
+    if (destination == NULL)
+        return NULL;
+    char *ptr = destination;
+    while (*source && num--)
+    {
+        *destination = *source;
+        destination++;
+        source++;
+    }
+    *destination = '\0';
+    return ptr;
+}
+
+char *strdup(const char *s)
+{
+    char *buf = (char *)__malloc(strlen((char *)s) + 1);
+    strncpy(buf, s, strlen(s) + 1);
+    return buf;
+}
+
+char *strchr(char const *s, int c)
+{
+    size_t len = strlen(s);
+    for (size_t i = 0; i < len; i++)
+        if (s[i] == c)
+            return (char *)s + i;
+
+    return NULL;
+}
+
+char *strrchr(char const *s, int c)
+{
+    size_t len = strlen(s);
+    size_t pos = len;
+
+    while (s[pos] != c && pos-- != 0)
+        ;
+
+    if (pos == len)
+        return NULL;
+
+    return (char *)s + pos;
+}
+
+void *memmove(void *dest, const void *src, size_t n)
+{
+    char *d = dest;
+    const char *s = src;
+    if (d < s)
+        while (n--)
+            *d++ = *s++;
+    else
+    {
+        const char *lasts = s + (n - 1);
+        char *lastd = d + (n - 1);
+        while (n--)
+            *lastd-- = *lasts--;
+    }
+    return dest;
+}
diff --git a/libc/src/std/sys_stat.c b/libc/src/std/sys_stat.c
new file mode 100644
index 0000000..0ba22d6
--- /dev/null
+++ b/libc/src/std/sys_stat.c
@@ -0,0 +1,16 @@
+#include <sys/stat.h>
+
+int mkdir(const char *path, mode_t mode)
+{
+    return 0;
+}
+
+int remove(const char *pathname)
+{
+    return 0;
+}
+
+int rename(const char *oldpath, const char *newpath)
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/libc/src/string.c b/libc/src/string.c
deleted file mode 100644
index 3ae0908..0000000
--- a/libc/src/string.c
+++ /dev/null
@@ -1,14 +0,0 @@
-#include <string.h>
-
-int strncmp(const char *s1, const char *s2, size_t n)
-{
-    for (size_t i = 0; i < n; i++)
-    {
-        char c1 = s1[i], c2 = s2[i];
-        if (c1 != c2)
-            return c1 - c2;
-        if (!c1)
-            return 0;
-    }
-    return 0;
-}