diff --git a/Userspace/libc/include/dirent.h b/Userspace/libc/include/dirent.h
index 80e02154..99ac3620 100644
--- a/Userspace/libc/include/dirent.h
+++ b/Userspace/libc/include/dirent.h
@@ -59,7 +59,7 @@ extern "C"
 #define DT_TMO
 
 	int alphasort(const struct dirent **, const struct dirent **);
-	int closedir(DIR *);
+	int closedir(DIR *dirp);
 	int dirfd(DIR *);
 	DIR *fdopendir(int);
 	DIR *opendir(const char *);
diff --git a/Userspace/libc/include/fcntl.h b/Userspace/libc/include/fcntl.h
index 039155b8..c444c77e 100644
--- a/Userspace/libc/include/fcntl.h
+++ b/Userspace/libc/include/fcntl.h
@@ -23,6 +23,8 @@ extern "C"
 {
 #endif // __cplusplus
 
+#include <sys/types.h>
+
 	typedef struct f_owner_ex
 	{
 		int type;  /* Discriminator for pid. */
diff --git a/Userspace/libc/include/stdio.h b/Userspace/libc/include/stdio.h
index 50ec245d..fee0fe7e 100644
--- a/Userspace/libc/include/stdio.h
+++ b/Userspace/libc/include/stdio.h
@@ -90,9 +90,9 @@ extern "C"
 	int feof(FILE *);
 	int ferror(FILE *);
 	int fflush(FILE *stream);
-	int fgetc(FILE *);
+	int fgetc(FILE *stream);
 	int fgetpos(FILE *restrict, fpos_t *restrict);
-	char *fgets(char *restrict, int, FILE *restrict);
+	char *fgets(char *restrict s, int n, FILE *restrict stream);
 	int fileno(FILE *);
 	void flockfile(FILE *);
 	FILE *fmemopen(void *restrict, size_t, const char *restrict);
@@ -119,7 +119,7 @@ extern "C"
 	ssize_t getline(char **restrict, size_t *restrict, FILE *restrict);
 	FILE *open_memstream(char **, size_t *);
 	int pclose(FILE *);
-	void perror(const char *);
+	void perror(const char *s);
 	FILE *popen(const char *, const char *);
 	int printf(const char *restrict format, ...);
 	int putc(int c, FILE *stream);
@@ -134,8 +134,8 @@ extern "C"
 	int scanf(const char *restrict, ...);
 	void setbuf(FILE *restrict, char *restrict);
 	int setvbuf(FILE *restrict, char *restrict, int, size_t);
-	int snprintf(char *restrict, size_t, const char *restrict, ...);
-	int sprintf(char *restrict, const char *restrict, ...);
+	int snprintf(char *restrict s, size_t n, const char *restrict format, ...);
+	int sprintf(char *restrict s, const char *restrict format, ...);
 	int sscanf(const char *restrict, const char *restrict, ...);
 	FILE *tmpfile(void);
 	char *tmpnam(char *);
diff --git a/Userspace/libc/include/stdlib.h b/Userspace/libc/include/stdlib.h
index 5191a601..478ee63f 100644
--- a/Userspace/libc/include/stdlib.h
+++ b/Userspace/libc/include/stdlib.h
@@ -51,7 +51,7 @@ extern "C"
 
 	long a64l(const char *);
 	void abort(void);
-	int abs(int);
+	int abs(int i);
 	int atexit(void (*func)(void));
 	double atof(const char *);
 	int atoi(const char *);
@@ -66,7 +66,7 @@ extern "C"
 	char *fcvt(double, int, int *, int *);
 	void free(void *ptr);
 	char *gcvt(double, int, char *);
-	char *getenv(const char *);
+	char *getenv(const char *name);
 	int getsubopt(char **, char *const *, char **);
 	int grantpt(int);
 	char *initstate(unsigned int, char *, size_t);
diff --git a/Userspace/libc/include/string.h b/Userspace/libc/include/string.h
index b77231cf..ac6578c3 100644
--- a/Userspace/libc/include/string.h
+++ b/Userspace/libc/include/string.h
@@ -36,7 +36,7 @@ extern "C"
 	char *stpcpy(char *restrict, const char *restrict);
 	char *stpncpy(char *restrict, const char *restrict, size_t);
 	char *strcat(char *restrict, const char *restrict);
-	char *strchr(const char *, int);
+	char *strchr(const char *s, int c);
 	int strcmp(const char *s1, const char *s2);
 	int strcoll(const char *, const char *);
 	int strcoll_l(const char *, const char *, locale_t);
@@ -48,19 +48,19 @@ extern "C"
 	int strerror_r(int, char *, size_t);
 	size_t strlcat(char *restrict, const char *restrict, size_t);
 	size_t strlcpy(char *restrict, const char *restrict, size_t);
-	size_t strlen(const char *);
+	size_t strlen(const char *s);
 	char *strncat(char *restrict, const char *restrict, size_t);
-	int strncmp(const char *, const char *, size_t);
+	int strncmp(const char *s1, const char *s2, size_t n);
 	char *strncpy(char *restrict, const char *restrict, size_t);
 	char *strndup(const char *, size_t);
 	size_t strnlen(const char *, size_t);
-	char *strpbrk(const char *, const char *);
+	char *strpbrk(const char *s1, const char *s2);
 	char *strrchr(const char *, int);
-	char *strsignal(int);
-	size_t strspn(const char *, const char *);
+	char *strsignal(int signum);
+	size_t strspn(const char *s1, const char *s2);
 	char *strstr(const char *, const char *);
-	char *strtok(char *restrict, const char *restrict);
-	char *strtok_r(char *restrict, const char *restrict, char **restrict);
+	char *strtok(char *restrict s, const char *restrict sep);
+	char *strtok_r(char *restrict s, const char *restrict sep, char **restrict state);
 	size_t strxfrm(char *restrict, const char *restrict, size_t);
 	size_t strxfrm_l(char *restrict, const char *restrict, size_t, locale_t);
 
diff --git a/Userspace/libc/include/sys/stat.h b/Userspace/libc/include/sys/stat.h
index 21a6b5c5..92d4a560 100644
--- a/Userspace/libc/include/sys/stat.h
+++ b/Userspace/libc/include/sys/stat.h
@@ -91,8 +91,8 @@ extern "C"
 	int fstatat(int, const char *restrict, struct stat *restrict, int);
 	int futimens(int, const struct timespec[2]);
 	int lstat(const char *restrict, struct stat *restrict);
-	int mkdir(const char *, mode_t);
-	int mkdirat(int, const char *, mode_t);
+	int mkdir(const char *path, mode_t mode);
+	int mkdirat(int fd, const char *path, mode_t mode);
 	int mkfifo(const char *, mode_t);
 	int mkfifoat(int, const char *, mode_t);
 	int mknod(const char *, mode_t, dev_t);
diff --git a/Userspace/libc/include/sys/wait.h b/Userspace/libc/include/sys/wait.h
index 032105de..a9914275 100644
--- a/Userspace/libc/include/sys/wait.h
+++ b/Userspace/libc/include/sys/wait.h
@@ -54,9 +54,9 @@ extern "C"
 	typedef unsigned int id_t;
 	typedef int pid_t;
 
-	pid_t wait(int *);
-	int waitid(idtype_t, id_t, siginfo_t *, int);
-	pid_t waitpid(pid_t, int *, int);
+	pid_t wait(int *stat_loc);
+	int waitid(idtype_t idtype, id_t id, siginfo_t *infop, int options);
+	pid_t waitpid(pid_t pid, int *stat_loc, int options);
 
 #ifdef __cplusplus
 }
diff --git a/Userspace/libc/include/unistd.h b/Userspace/libc/include/unistd.h
index 068bad8f..759f8ceb 100644
--- a/Userspace/libc/include/unistd.h
+++ b/Userspace/libc/include/unistd.h
@@ -57,9 +57,10 @@ extern "C"
 
 	extern char *optarg;
 	extern int optind, opterr, optopt;
+	extern char **environ;
 
 	int access(const char *, int);
-	unsigned int alarm(unsigned int);
+	unsigned int alarm(unsigned int seconds);
 	int brk(void *);
 	int chdir(const char *);
 	int chroot(const char *);
@@ -72,12 +73,12 @@ extern "C"
 	int dup(int);
 	int dup2(int, int);
 	void encrypt(char[64], int);
-	int execl(const char *, const char *, ...);
-	int execle(const char *, const char *, ...);
-	int execlp(const char *, const char *, ...);
-	int execv(const char *, char *const[]);
-	int execve(const char *, char *const[], char *const[]);
-	int execvp(const char *, char *const[]);
+	int execl(const char *path, const char *arg0, ... /*, (char *)0 */);
+	int execle(const char *path, const char *arg0, ... /*, (char *)0, char *const envp[]*/);
+	int execlp(const char *file, const char *arg0, ... /*, (char *)0 */);
+	int execv(const char *path, char *const argv[]);
+	int execve(const char *path, char *const argv[], char *const envp[]);
+	int execvp(const char *file, char *const argv[]);
 	void _exit(int);
 	int fchown(int, uid_t, gid_t);
 	int fchdir(int);
@@ -128,7 +129,7 @@ extern "C"
 	int setreuid(uid_t, uid_t);
 	pid_t setsid(void);
 	int setuid(uid_t);
-	unsigned int sleep(unsigned int);
+	unsigned int sleep(unsigned int seconds);
 	void swab(const void *, void *, ssize_t);
 	int symlink(const char *, const char *);
 	void sync(void);
diff --git a/Userspace/libc/src/std/dirent.c b/Userspace/libc/src/std/dirent.c
new file mode 100644
index 00000000..f0ff6b3d
--- /dev/null
+++ b/Userspace/libc/src/std/dirent.c
@@ -0,0 +1,57 @@
+/*
+	This file is part of Fennix C Library.
+
+	Fennix C Library 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.
+
+	Fennix C Library 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 Fennix C Library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <dirent.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+export int alphasort(const struct dirent **, const struct dirent **);
+
+export int closedir(DIR *dirp)
+{
+	if (!dirp)
+	{
+		errno = EBADF;
+		return -1;
+	}
+
+	int fd = dirfd(dirp);
+	if (fd == -1)
+	{
+		errno = EBADF;
+		return -1;
+	}
+
+	int result = close(fd);
+	if (result == -1)
+		return -1;
+
+	free(dirp);
+	return 0;
+}
+
+export int dirfd(DIR *);
+export DIR *fdopendir(int);
+export DIR *opendir(const char *);
+export ssize_t posix_getdents(int, void *, size_t, int);
+export struct dirent *readdir(DIR *);
+export int readdir_r(DIR *restrict, struct dirent *restrict, struct dirent **restrict);
+export void rewinddir(DIR *);
+export int scandir(const char *, struct dirent ***, int (*)(const struct dirent *), int (*)(const struct dirent **, const struct dirent **));
+export void seekdir(DIR *, long);
+export long telldir(DIR *);
diff --git a/Userspace/libc/src/std/stdio.c b/Userspace/libc/src/std/stdio.c
index bde21155..602da4f9 100644
--- a/Userspace/libc/src/std/stdio.c
+++ b/Userspace/libc/src/std/stdio.c
@@ -18,6 +18,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
 #include <fennix/syscalls.h>
 #include "../print/printf.h"
 
@@ -109,9 +110,54 @@ export int fflush(FILE *stream)
 	return 0;
 }
 
-export int fgetc(FILE *);
+export int fgetc(FILE *stream)
+{
+	if (!stream || !(stream->flags & _i_READ))
+		return EOF;
+
+	if (stream->buffer_pos >= stream->buffer_size)
+	{
+		int res = call_read(stream->fd, stream->buffer, 4096);
+		if (res <= 0)
+		{
+			if (res == 0)
+				stream->eof = 1;
+			else
+				stream->error = 1;
+			return EOF;
+		}
+		stream->buffer_pos = 0;
+		stream->buffer_size = res;
+	}
+
+	return (unsigned char)stream->buffer[stream->buffer_pos++];
+}
+
 export int fgetpos(FILE *restrict, fpos_t *restrict);
-export char *fgets(char *restrict, int, FILE *restrict);
+
+export char *fgets(char *restrict s, int n, FILE *restrict stream)
+{
+	if (!s || n <= 0 || !stream)
+		return NULL;
+
+	int i = 0;
+	while (i < n - 1)
+	{
+		int c = fgetc(stream);
+		if (c == EOF)
+		{
+			if (i == 0)
+				return NULL;
+			break;
+		}
+		s[i++] = (char)c;
+		if (c == '\n')
+			break;
+	}
+	s[i] = '\0';
+	return s;
+}
+
 export int fileno(FILE *);
 export void flockfile(FILE *);
 export FILE *fmemopen(void *restrict, size_t, const char *restrict);
@@ -302,7 +348,15 @@ export ssize_t getdelim(char **restrict, size_t *restrict, int, FILE *restrict);
 export ssize_t getline(char **restrict, size_t *restrict, FILE *restrict);
 export FILE *open_memstream(char **, size_t *);
 export int pclose(FILE *);
-export void perror(const char *);
+
+export void perror(const char *s)
+{
+	fputs(s, stderr);
+	fputs(": ", stderr);
+	fputs(strerror(errno), stderr);
+	fputc('\n', stderr);
+}
+
 export FILE *popen(const char *, const char *);
 
 export int printf(const char *restrict format, ...)
@@ -327,8 +381,25 @@ export void rewind(FILE *);
 export int scanf(const char *restrict, ...);
 export void setbuf(FILE *restrict, char *restrict);
 export int setvbuf(FILE *restrict, char *restrict, int, size_t);
-export int snprintf(char *restrict, size_t, const char *restrict, ...);
-export int sprintf(char *restrict, const char *restrict, ...);
+
+export int snprintf(char *restrict s, size_t n, const char *restrict format, ...)
+{
+	va_list args;
+	va_start(args, format);
+	int ret = vsnprintf_(s, n, format, args);
+	va_end(args);
+	return ret;
+}
+
+export int sprintf(char *restrict s, const char *restrict format, ...)
+{
+	va_list args;
+	va_start(args, format);
+	int ret = vsprintf_(s, format, args);
+	va_end(args);
+	return ret;
+}
+
 export int sscanf(const char *restrict, const char *restrict, ...);
 export FILE *tmpfile(void);
 export char *tmpnam(char *);
diff --git a/Userspace/libc/src/std/stdlib.c b/Userspace/libc/src/std/stdlib.c
index 4a31ac51..c8f177e8 100644
--- a/Userspace/libc/src/std/stdlib.c
+++ b/Userspace/libc/src/std/stdlib.c
@@ -17,6 +17,7 @@
 
 #include <stdlib.h>
 #include <unistd.h>
+#include <string.h>
 #include "../mem/liballoc_1_1.h"
 
 #define MAX_ATEXIT_FUNCS 32
@@ -31,7 +32,10 @@ export _Noreturn void abort(void)
 	__builtin_unreachable();
 }
 
-export int abs(int);
+export int abs(int i)
+{
+	return (i < 0) ? -i : i;
+}
 
 export int atexit(void (*func)(void))
 {
@@ -62,7 +66,18 @@ export void exit(int status)
 export char *fcvt(double, int, int *, int *);
 export void free(void *ptr) { return PREFIX(free)(ptr); }
 export char *gcvt(double, int, char *);
-export char *getenv(const char *);
+
+export char *getenv(const char *name)
+{
+	for (char **env = environ; *env != 0; ++env)
+	{
+		char *thisEnv = *env;
+		if (strncmp(thisEnv, name, strlen(name)) == 0 && thisEnv[strlen(name)] == '=')
+			return thisEnv + strlen(name) + 1;
+	}
+	return NULL;
+}
+
 export int getsubopt(char **, char *const *, char **);
 export int grantpt(int);
 export char *initstate(unsigned int, char *, size_t);
diff --git a/Userspace/libc/src/std/string.c b/Userspace/libc/src/std/string.c
index a283583a..0307adca 100644
--- a/Userspace/libc/src/std/string.c
+++ b/Userspace/libc/src/std/string.c
@@ -17,6 +17,7 @@
 
 #include <sys/types.h>
 #include <string.h>
+#include <fennix/syscalls.h>
 
 export void *memccpy(void *restrict, const void *restrict, int, size_t);
 export void *memchr(const void *, int, size_t);
@@ -46,7 +47,19 @@ export void *memset(void *, int, size_t);
 export char *stpcpy(char *restrict, const char *restrict);
 export char *stpncpy(char *restrict, const char *restrict, size_t);
 export char *strcat(char *restrict, const char *restrict);
-export char *strchr(const char *, int);
+
+export char *strchr(const char *s, int c)
+{
+	while (*s)
+	{
+		if (*s == (char)c)
+			return (char *)s;
+		s++;
+	}
+	if (c == '\0')
+		return (char *)s;
+	return NULL;
+}
 
 export int strcmp(const char *s1, const char *s2)
 {
@@ -69,18 +82,171 @@ export char *strerror_l(int, locale_t);
 export int strerror_r(int, char *, size_t);
 export size_t strlcat(char *restrict, const char *restrict, size_t);
 export size_t strlcpy(char *restrict, const char *restrict, size_t);
-export size_t strlen(const char *);
+
+export size_t strlen(const char *s)
+{
+	const char *start = s;
+	while (*s)
+		s++;
+	return s - start;
+}
+
 export char *strncat(char *restrict, const char *restrict, size_t);
-export int strncmp(const char *, const char *, size_t);
+
+export int strncmp(const char *s1, const char *s2, size_t n)
+{
+	while (n--)
+	{
+		if (*s1 != *s2)
+			return *(unsigned char *)s1 - *(unsigned char *)s2;
+		if (*s1 == '\0')
+			return 0;
+		s1++;
+		s2++;
+	}
+	return 0;
+}
+
 export char *strncpy(char *restrict, const char *restrict, size_t);
 export char *strndup(const char *, size_t);
 export size_t strnlen(const char *, size_t);
-export char *strpbrk(const char *, const char *);
+
+export char *strpbrk(const char *s1, const char *s2)
+{
+	while (*s1)
+	{
+		const char *s = s2;
+		while (*s)
+		{
+			if (*s1 == *s)
+				return (char *)s1;
+			s++;
+		}
+		s1++;
+	}
+	return NULL;
+}
+
 export char *strrchr(const char *, int);
-export char *strsignal(int);
-export size_t strspn(const char *, const char *);
+
+export char *strsignal(int signum)
+{
+	switch (signum)
+	{
+	case __SYS_SIGNULL:
+		return "NULL signal";
+	case __SYS_SIGABRT:
+		return "Aborted";
+	case __SYS_SIGALRM:
+		return "Alarm clock";
+	case __SYS_SIGBUS:
+		return "Bus error";
+	case __SYS_SIGCHLD:
+		return "Child status changed";
+	case __SYS_SIGCONT:
+		return "Continued";
+	case __SYS_SIGFPE:
+		return "Arithmetic exception";
+	case __SYS_SIGHUP:
+		return "Hangup";
+	case __SYS_SIGILL:
+		return "Illegal instruction";
+	case __SYS_SIGINT:
+		return "Interrupt";
+	case __SYS_SIGKILL:
+		return "Killed";
+	case __SYS_SIGPIPE:
+		return "Broken pipe";
+	case __SYS_SIGQUIT:
+		return "Quit";
+	case __SYS_SIGSEGV:
+		return "Segmentation fault";
+	case __SYS_SIGSTOP:
+		return "Stopped (signal)";
+	case __SYS_SIGTERM:
+		return "Terminated";
+	case __SYS_SIGTSTP:
+		return "Stopped (user)";
+	case __SYS_SIGTTIN:
+		return "Stopped (tty input)";
+	case __SYS_SIGTTOU:
+		return "Stopped (tty output)";
+	case __SYS_SIGUSR1:
+		return "User defined signal 1";
+	case __SYS_SIGUSR2:
+		return "User defined signal 2";
+	case __SYS_SIGPOLL:
+		return "Pollable event occurred";
+	case __SYS_SIGPROF:
+		return "Profiling timer expired";
+	case __SYS_SIGSYS:
+		return "Bad system call";
+	case __SYS_SIGTRAP:
+		return "Trace/breakpoint trap";
+	case __SYS_SIGURG:
+		return "Urgent I/O condition";
+	case __SYS_SIGVTALRM:
+		return "Virtual timer expired";
+	case __SYS_SIGXCPU:
+		return "CPU time limit exceeded";
+	case __SYS_SIGXFSZ:
+		return "File size limit exceeded";
+	default:
+		return NULL;
+	}
+}
+
+export size_t strspn(const char *s1, const char *s2)
+{
+	const char *p = s1;
+	const char *spanp;
+	char c, sc;
+
+cont:
+	c = *p++;
+	for (spanp = s2; (sc = *spanp++) != 0;)
+	{
+		if (sc == c)
+			goto cont;
+	}
+	return p - 1 - s1;
+}
+
 export char *strstr(const char *, const char *);
-export char *strtok(char *restrict, const char *restrict);
-export char *strtok_r(char *restrict, const char *restrict, char **restrict);
+
+export char *strtok(char *restrict s, const char *restrict sep)
+{
+	static char *last;
+	return strtok_r(s, sep, &last);
+}
+
+export char *strtok_r(char *restrict s, const char *restrict sep, char **restrict state)
+{
+	char *start;
+	char *end;
+
+	if (s == NULL)
+		s = *state;
+
+	s += strspn(s, sep);
+	if (*s == '\0')
+	{
+		*state = s;
+		return NULL;
+	}
+
+	start = s;
+	end = strpbrk(start, sep);
+	if (end)
+	{
+		*end = '\0';
+		*state = end + 1;
+	}
+	else
+		*state = start + strlen(start);
+
+	return start;
+}
+
 export size_t strxfrm(char *restrict, const char *restrict, size_t);
 export size_t strxfrm_l(char *restrict, const char *restrict, size_t, locale_t);
diff --git a/Userspace/libc/src/std/sys/stat.c b/Userspace/libc/src/std/sys/stat.c
new file mode 100644
index 00000000..6de4f2d3
--- /dev/null
+++ b/Userspace/libc/src/std/sys/stat.c
@@ -0,0 +1,47 @@
+/*
+	This file is part of Fennix C Library.
+
+	Fennix C Library 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.
+
+	Fennix C Library 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 Fennix C Library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <sys/stat.h>
+#include <errno.h>
+#include <stdio.h>
+
+export int chmod(const char *, mode_t);
+export int fchmod(int, mode_t);
+export int fchmodat(int, const char *, mode_t, int);
+export int fstat(int, struct stat *);
+export int fstatat(int, const char *restrict, struct stat *restrict, int);
+export int futimens(int, const struct timespec[2]);
+export int lstat(const char *restrict, struct stat *restrict);
+
+export int mkdir(const char *path, mode_t mode)
+{
+	return __check_errno(call_mkdir(path, mode), -1);
+}
+
+export int mkdirat(int fd, const char *path, mode_t mode)
+{
+	printf("mkdirat() is unimplemented\n");
+	return __check_errno(-ENOSYS, -1);
+}
+
+export int mkfifo(const char *, mode_t);
+export int mkfifoat(int, const char *, mode_t);
+export int mknod(const char *, mode_t, dev_t);
+export int mknodat(int, const char *, mode_t, dev_t);
+export int stat(const char *restrict, struct stat *restrict);
+export mode_t umask(mode_t);
+export int utimensat(int, const char *, const struct timespec[2], int);
diff --git a/Userspace/libc/src/std/sys/wait.c b/Userspace/libc/src/std/sys/wait.c
new file mode 100644
index 00000000..6b0ef80d
--- /dev/null
+++ b/Userspace/libc/src/std/sys/wait.c
@@ -0,0 +1,38 @@
+/*
+	This file is part of Fennix C Library.
+
+	Fennix C Library 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.
+
+	Fennix C Library 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 Fennix C Library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <sys/wait.h>
+#include <fennix/syscalls.h>
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+
+export pid_t wait(int *stat_loc)
+{
+	return waitpid((pid_t)-1, stat_loc, 0);
+}
+
+export int waitid(idtype_t idtype, id_t id, siginfo_t *infop, int options)
+{
+	printf("waitid() is unimplemented\n");
+	return __check_errno(-ENOSYS, -1);
+}
+
+export pid_t waitpid(pid_t pid, int *stat_loc, int options)
+{
+	return __check_errno(call_waitpid(pid, stat_loc, options), -1);
+}
diff --git a/Userspace/libc/src/std/unistd.c b/Userspace/libc/src/std/unistd.c
index 53388fb8..5702edb4 100644
--- a/Userspace/libc/src/std/unistd.c
+++ b/Userspace/libc/src/std/unistd.c
@@ -16,13 +16,26 @@
 */
 
 #include <unistd.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
 #include <fennix/syscalls.h>
 
 export char *optarg;
 export int optind, opterr, optopt;
+export char **environ;
 
 export int access(const char *, int);
-export unsigned int alarm(unsigned int);
+
+export unsigned int alarm(unsigned int seconds)
+{
+	printf("alarm() is unimplemented\n");
+	return __check_errno(-ENOSYS, -1);
+}
+
 export int brk(void *);
 export int chdir(const char *);
 export int chroot(const char *);
@@ -35,17 +48,122 @@ export char *cuserid(char *s);
 export int dup(int);
 export int dup2(int, int);
 export void encrypt(char[64], int);
-export int execl(const char *, const char *, ...);
-export int execle(const char *, const char *, ...);
-export int execlp(const char *, const char *, ...);
-export int execv(const char *, char *const[]);
-export int execve(const char *, char *const[], char *const[]);
-export int execvp(const char *, char *const[]);
+
+export int execl(const char *path, const char *arg0, ...)
+{
+	va_list args;
+	va_start(args, arg0);
+
+	int argc = 1;
+	while (va_arg(args, const char *))
+		argc++;
+	va_end(args);
+
+	char *argv[argc + 1];
+	va_start(args, arg0);
+	argv[0] = (char *)arg0;
+	for (int i = 1; i < argc; i++)
+		argv[i] = va_arg(args, char *);
+
+	argv[argc] = NULL;
+	va_end(args);
+	return execve(path, argv, environ);
+}
+
+export int execle(const char *path, const char *arg0, ...)
+{
+	va_list args;
+	va_start(args, arg0);
+
+	int argc = 1;
+	while (va_arg(args, const char *))
+		argc++;
+	va_end(args);
+
+	char *argv[argc + 1];
+	va_start(args, arg0);
+	argv[0] = (char *)arg0;
+	for (int i = 1; i < argc; i++)
+		argv[i] = va_arg(args, char *);
+
+	argv[argc] = NULL;
+
+	char *const *envp = va_arg(args, char *const *);
+	va_end(args);
+
+	return execve(path, argv, envp);
+}
+
+export int execlp(const char *file, const char *arg0, ...)
+{
+	va_list args;
+	va_start(args, arg0);
+
+	int argc = 1;
+	while (va_arg(args, const char *))
+		argc++;
+
+	va_end(args);
+
+	char *argv[argc + 1];
+	va_start(args, arg0);
+	argv[0] = (char *)arg0;
+	for (int i = 1; i < argc; i++)
+		argv[i] = va_arg(args, char *);
+
+	argv[argc] = NULL;
+	va_end(args);
+
+	return execvp(file, argv);
+}
+
+export int execv(const char *path, char *const argv[])
+{
+	return execve(path, argv, environ);
+}
+
+export int execve(const char *path, char *const argv[], char *const envp[])
+{
+	return __check_errno(call_execve(path, argv, envp), -1);
+}
+
+export int execvp(const char *file, char *const argv[])
+{
+	if (strchr(file, '/'))
+		return execve(file, argv, environ);
+
+	char *path = getenv("PATH");
+	if (!path)
+	{
+		errno = ENOENT;
+		return -1;
+	}
+
+	char *p = strtok(path, ":");
+	while (p)
+	{
+		char fullpath[PATH_MAX];
+		snprintf(fullpath, sizeof(fullpath), "%s/%s", p, file);
+		execve(fullpath, argv, environ);
+		if (errno != ENOENT && errno != ENOTDIR)
+			return -1;
+		p = strtok(NULL, ":");
+	}
+
+	errno = ENOENT;
+	return -1;
+}
+
 export void _exit(int);
 export int fchown(int, uid_t, gid_t);
 export int fchdir(int);
 export int fdatasync(int);
-export pid_t fork(void);
+
+export pid_t fork(void)
+{
+	return __check_errno(call_fork(), -1);
+}
+
 export long int fpathconf(int, int);
 export int fsync(int);
 export int ftruncate(int, off_t);
@@ -79,7 +197,13 @@ export int lockf(int, int, off_t);
 export off_t lseek(int, off_t, int);
 export int nice(int);
 export long int pathconf(const char *, int);
-export int pause(void);
+
+export int pause(void)
+{
+	printf("pause() is unimplemented\n");
+	return __check_errno(-ENOSYS, -1);
+}
+
 export int pipe(int[2]);
 export ssize_t pread(int, void *, size_t, off_t);
 export int pthread_atfork(void (*)(void), void (*)(void), void (*)(void));
@@ -95,10 +219,31 @@ export int setregid(gid_t, gid_t);
 export int setreuid(uid_t, uid_t);
 export pid_t setsid(void);
 export int setuid(uid_t);
-export unsigned int sleep(unsigned int);
+
+export unsigned int sleep(unsigned int seconds)
+{
+	unsigned int unslept = alarm(0); /* Cancel any existing alarm */
+	if (unslept > 0)
+	{
+		alarm(unslept); /* Restore the previous alarm if it was set */
+		return unslept;
+	}
+
+	alarm(seconds); /* Set the alarm for the requested sleep time */
+	pause();		/* Suspend execution until a signal is received */
+
+	unslept = alarm(0); /* Cancel the alarm and get the remaining time */
+	return unslept;
+}
+
 export void swab(const void *, void *, ssize_t);
 export int symlink(const char *, const char *);
-export void sync(void);
+
+export void sync(void)
+{
+	printf("sync() is unimplemented\n");
+}
+
 export long int sysconf(int);
 export pid_t tcgetpgrp(int);
 export int tcsetpgrp(int, pid_t);