libc: split up large .c files, slimming down small binaries a bit

15 files changed, 503 insertions, 483 deletions

diff --git a/src/cmd/true/true.c b/src/cmd/true/true.c
new file mode 100644
index 0000000..061ed7e
--- /dev/null
+++ b/src/cmd/true/true.c
@@ -0,0 +1,3 @@
+int main(void) {
+	return 0;
+}
diff --git a/src/libc/_start2.c b/src/libc/_start2.c
index b4eb76a..dbc91d7 100644
--- a/src/libc/_start2.c
+++ b/src/libc/_start2.c
@@ -36,7 +36,7 @@ _Noreturn void _start2(struct execdata *ed) {
 
 	_sys_intr_set(intr_trampoline);
 	intr_set(intr_default);
-	__setinitialcwd(ed->cwd);
+	__initialcwd = ed->cwd;
 
 	exit(main(ed->argc, ed->argv, ed->envp));
 }
diff --git a/src/libc/include/camellia/intr.h b/src/libc/include/camellia/intr.h
new file mode 100644
index 0000000..b9390fd
--- /dev/null
+++ b/src/libc/include/camellia/intr.h
@@ -0,0 +1,4 @@
+#pragma once
+
+void intr_set(void (*fn)(void));
+void intr_default(void);
diff --git a/src/libc/include/unistd.h b/src/libc/include/unistd.h
index 750d6e2..2158511 100644
--- a/src/libc/include/unistd.h
+++ b/src/libc/include/unistd.h
@@ -1,5 +1,6 @@
 #pragma once
 #include <camellia/types.h> // TODO only needed because of hid_t
+#include <camellia/intr.h> // TODO only included for backwards compat
 #include <sys/types.h>
 #include <getopt.h>
 
@@ -64,8 +65,5 @@ unsigned int sleep(unsigned int seconds);
  * @return 0 on failure, length of the path otherwise */
 size_t absolutepath(char *out, const char *in, size_t size);
 
-// TODO put in an internal libc header
-void __setinitialcwd(const char *c);
-
-void intr_set(void (*fn)(void));
-void intr_default(void);
+/* used internally */
+extern const char *__initialcwd;
diff --git a/src/libc/intr.c b/src/libc/intr.c
new file mode 100644
index 0000000..cdefc2f
--- /dev/null
+++ b/src/libc/intr.c
@@ -0,0 +1,13 @@
+#include <camellia/intr.h>
+#include <stdlib.h>
+
+static void intr_null(void) { }
+
+extern void (*volatile _intr)(void);
+void intr_set(void (*fn)(void)) {
+	_intr = fn ? fn : intr_null;
+}
+
+void intr_default(void) {
+	exit(-1);
+}
diff --git a/src/libc/printf.c b/src/libc/stdio/fprintf.c
index a760240..cd2851c 100644
--- a/src/libc/printf.c
+++ b/src/libc/stdio/fprintf.c
@@ -1,27 +1,10 @@
-#include <camellia/syscalls.h>
 #include <shared/printf.h>
 #include <stdio.h>
-#include <string.h>
-
 
 static void backend_file(void *arg, const char *buf, size_t len) {
 	fwrite(buf, 1, len, arg);
 }
 
-int vfprintf(FILE *restrict f, const char *restrict fmt, va_list ap) {
-	return __printf_internal(fmt, ap, backend_file, f);
-}
-
-
-int printf(const char *restrict fmt, ...) {
-	int ret;
-	va_list argp;
-	va_start(argp, fmt);
-	ret = vprintf(fmt, argp);
-	va_end(argp);
-	return ret;
-}
-
 int fprintf(FILE *restrict f, const char *restrict fmt, ...) {
 	int ret;
 	va_list argp;
@@ -31,11 +14,15 @@ int fprintf(FILE *restrict f, const char *restrict fmt, ...) {
 	return ret;
 }
 
-int sprintf(char *restrict s, const char *restrict fmt, ...) {
+int vfprintf(FILE *restrict f, const char *restrict fmt, va_list ap) {
+	return __printf_internal(fmt, ap, backend_file, f);
+}
+
+int printf(const char *restrict fmt, ...) {
 	int ret;
 	va_list argp;
 	va_start(argp, fmt);
-	ret = vsnprintf(s, ~0, fmt, argp);
+	ret = vprintf(fmt, argp);
 	va_end(argp);
 	return ret;
 }
@@ -43,18 +30,3 @@ int sprintf(char *restrict s, const char *restrict fmt, ...) {
 int vprintf(const char *restrict fmt, va_list ap) {
 	return vfprintf(stdout, fmt, ap);
 }
-
-int vsprintf(char *restrict s, const char *restrict fmt, va_list ap) {
-	return vsnprintf(s, ~0, fmt, ap);
-}
-
-int _klogf(const char *fmt, ...) {
-	char buf[256];
-	int ret;
-	va_list argp;
-	va_start(argp, fmt);
-	ret = vsnprintf(buf, sizeof buf, fmt, argp);
-	va_end(argp);
-	_sys_debug_klog(buf, ret);
-	return ret;
-}
diff --git a/src/libc/stdio/sprintf.c b/src/libc/stdio/sprintf.c
new file mode 100644
index 0000000..0bfbb17
--- /dev/null
+++ b/src/libc/stdio/sprintf.c
@@ -0,0 +1,28 @@
+#include <camellia/syscalls.h>
+#include <shared/mem.h>
+#include <shared/printf.h>
+#include <stdio.h>
+
+int sprintf(char *restrict s, const char *restrict fmt, ...) {
+	int ret;
+	va_list argp;
+	va_start(argp, fmt);
+	ret = vsnprintf(s, ~0, fmt, argp);
+	va_end(argp);
+	return ret;
+}
+
+int vsprintf(char *restrict s, const char *restrict fmt, va_list ap) {
+	return vsnprintf(s, ~0, fmt, ap);
+}
+
+int _klogf(const char *fmt, ...) {
+	char buf[256];
+	int ret;
+	va_list argp;
+	va_start(argp, fmt);
+	ret = vsnprintf(buf, sizeof buf, fmt, argp);
+	va_end(argp);
+	_sys_debug_klog(buf, ret);
+	return ret;
+}
diff --git a/src/libc/stdlib/progname.c b/src/libc/stdlib/progname.c
new file mode 100644
index 0000000..4cc0fb2
--- /dev/null
+++ b/src/libc/stdlib/progname.c
@@ -0,0 +1,28 @@
+#include <_proc.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static const char *progname;
+const char *getprogname(void) {
+	return progname;
+}
+void setprogname(const char *pg) {
+	progname = pg;
+	setproctitle(NULL);
+}
+
+void setproctitle(const char *fmt, ...) {
+	// TODO bounds checking
+	if (!fmt) {
+		strcpy(_psdata_loc->desc, progname);
+		return;
+	}
+	sprintf(_psdata_loc->desc, "%s: ", progname);
+
+	va_list argp;
+	va_start(argp, fmt);
+	vsnprintf(_psdata_loc->desc + strlen(_psdata_loc->desc), 128, fmt, argp);
+	va_end(argp);
+}
+
diff --git a/src/libc/stdlib.c b/src/libc/stdlib/stdlib.c
index 16c8f70..1dee760 100644
--- a/src/libc/stdlib.c
+++ b/src/libc/stdlib/stdlib.c
@@ -1,4 +1,3 @@
-#include <_proc.h>
 #include <bits/panic.h>
 #include <camellia.h>
 #include <camellia/syscalls.h>
@@ -10,29 +9,6 @@ _Noreturn void abort(void) {
 	_sys_exit(1);
 }
 
-static const char *progname;
-const char *getprogname(void) {
-	return progname;
-}
-void setprogname(const char *pg) {
-	progname = pg;
-	setproctitle(NULL);
-}
-
-void setproctitle(const char *fmt, ...) {
-	// TODO bounds checking
-	if (!fmt) {
-		strcpy(_psdata_loc->desc, progname);
-		return;
-	}
-	sprintf(_psdata_loc->desc, "%s: ", progname);
-
-	va_list argp;
-	va_start(argp, fmt);
-	vsnprintf(_psdata_loc->desc + strlen(_psdata_loc->desc), 128, fmt, argp);
-	va_end(argp);
-}
-
 char *mktemp(char *tmpl) {
 	// TODO mktemp mkstemp
 	return tmpl;
diff --git a/src/libc/string/basic.c b/src/libc/string/basic.c
new file mode 100644
index 0000000..902779b
--- /dev/null
+++ b/src/libc/string/basic.c
@@ -0,0 +1,105 @@
+/** String functions that don't depend on any external functions. */
+
+#include <string.h>
+
+char *strchr(const char *s, int c) {
+	for (; *s || c == 0; s++) {
+		if (*s == c) return (char *)s;
+	}
+	return NULL;
+}
+
+char *strrchr(const char *s, int c) {
+	for (int i = strlen(s) + 1; i >= 0; i--) {
+		if (s[i] == c) return (char *)s + i;
+	}
+	return NULL;
+}
+
+size_t strspn(const char *s, const char *accept) {
+	size_t l = 0;
+	for (; s[l] && strchr(accept, s[l]); l++);
+	return l;
+}
+
+size_t strcspn(const char *s, const char *reject) {
+	size_t l = 0;
+	for (; s[l] && !strchr(reject, s[l]); l++);
+	return l;
+}
+
+char *strpbrk(const char *s1, const char *s2) {
+	for (; *s1; s1++) {
+		if (strchr(s2, *s1)) return (char*)s1;
+	}
+	return NULL;
+}
+
+char *strtok(char *restrict s, const char *restrict sep) {
+	static char *state;
+	return strtok_r(s, sep, &state);
+}
+
+char *strtok_r(char *restrict s, const char *restrict sep, char **restrict state) {
+	char *end;
+	if (!s) s = *state;
+	s += strspn(s, sep); /* beginning of token */
+	if (!*s) return NULL;
+
+	end = s + strcspn(s, sep);
+	if (*end) {
+		*end = '\0';
+		*state = end + 1;
+	} else {
+		*state = end;
+	}
+	return s;
+}
+
+int strncmp(const char *s1, const char *s2, size_t n) {
+	for (size_t i = 0; i < n; i++) {
+		if (s1[i] < s2[i]) return -1;
+		if (s1[i] > s2[i]) return  1;
+	}
+	return 0;
+}
+
+int strcoll(const char *s1, const char *s2) {
+	return strcmp(s1, s2);
+}
+
+char *strstr(const char *s1, const char *s2) {
+	size_t l1 = strlen(s1), l2 = strlen(s2);
+	for (; l2 <= l1; s1++, l1--) {
+		if (memcmp(s1, s2, l2) == 0) return (char*)s1;
+	}
+	return NULL;
+}
+
+char *strcat(char *restrict dst, const char *restrict src) {
+	return strcpy(dst + strlen(dst), src);
+}
+
+char *strcpy(char *restrict s1, const char *restrict s2) {
+	char *ret = s1;
+	while (*s2) *s1++ = *s2++;
+	*s1 = *s2;
+	return ret;
+}
+
+char *strncpy(char *restrict dst, const char *restrict src, size_t n) {
+	for (size_t i = 0; i < n; i++) {
+		dst[i] = src[i];
+		if (dst[i] == '\0') return dst + i; // TODO fill with null bytes
+	}
+	return dst;
+}
+
+size_t strnlen(const char *s, size_t len) {
+	for (size_t i = 0; i < len; i++) {
+		if (!s[i]) {
+			return i;
+		}
+	}
+	return len;
+}
diff --git a/src/libc/string/string.c b/src/libc/string/string.c
index 748b0b5..e93b0a6 100644
--- a/src/libc/string/string.c
+++ b/src/libc/string/string.c
@@ -1,3 +1,5 @@
+/** String functions that don't fit into any of the other .c files */
+
 #include <bits/panic.h>
 #include <ctype.h>
 #include <errno.h>
@@ -5,107 +7,14 @@
 #include <string.h>
 #include <strings.h>
 
-char *strchr(const char *s, int c) {
-	for (; *s || c == 0; s++) {
-		if (*s == c) return (char *)s;
-	}
-	return NULL;
-}
-
-char *strrchr(const char *s, int c) {
-	for (int i = strlen(s) + 1; i >= 0; i--) {
-		if (s[i] == c) return (char *)s + i;
-	}
-	return NULL;
-}
-
-size_t strspn(const char *s, const char *accept) {
-	size_t l = 0;
-	for (; s[l] && strchr(accept, s[l]); l++);
-	return l;
-}
-
-size_t strcspn(const char *s, const char *reject) {
-	size_t l = 0;
-	for (; s[l] && !strchr(reject, s[l]); l++);
-	return l;
-}
-
-char *strpbrk(const char *s1, const char *s2) {
-	for (; *s1; s1++) {
-		if (strchr(s2, *s1)) return (char*)s1;
-	}
-	return NULL;
-}
-
-char *strtok(char *restrict s, const char *restrict sep) {
-	static char *state;
-	return strtok_r(s, sep, &state);
-}
-
-char *strtok_r(char *restrict s, const char *restrict sep, char **restrict state) {
-	char *end;
-	if (!s) s = *state;
-	s += strspn(s, sep); /* beginning of token */
-	if (!*s) return NULL;
-
-	end = s + strcspn(s, sep);
-	if (*end) {
-		*end = '\0';
-		*state = end + 1;
-	} else {
-		*state = end;
-	}
-	return s;
-}
-
-int strncmp(const char *s1, const char *s2, size_t n) {
-	for (size_t i = 0; i < n; i++) {
-		if (s1[i] < s2[i]) return -1;
-		if (s1[i] > s2[i]) return  1;
-	}
-	return 0;
-}
-
-int strcoll(const char *s1, const char *s2) {
-	return strcmp(s1, s2);
-}
-
-// TODO implement strstr using Boyer-Moore
-char *strstr(const char *s1, const char *s2) {
-	size_t l1 = strlen(s1), l2 = strlen(s2);
-	for (; l2 <= l1; s1++, l1--) {
-		if (memcmp(s1, s2, l2) == 0) return (char*)s1;
-	}
-	return NULL;
-}
-
-char *strcat(char *restrict dst, const char *restrict src) {
-	return strcpy(dst + strlen(dst), src);
-}
-
-char *strcpy(char *restrict s1, const char *restrict s2) {
-	char *ret = s1;
-	while (*s2) *s1++ = *s2++;
-	*s1 = *s2;
-	return ret;
-}
-
-char *strncpy(char *restrict dst, const char *restrict src, size_t n) {
-	for (size_t i = 0; i < n; i++) {
-		dst[i] = src[i];
-		if (dst[i] == '\0') return dst + i; // TODO fill with null bytes
-	}
-	return dst;
-}
-
 char *strncat(char *restrict dst, const char *restrict src, size_t n) {
 	(void)dst; (void)src; (void)n;
 	__libc_panic("unimplemented");
 }
 
 char *stpncpy(char *restrict dst, const char *restrict src, size_t n) {
-	return stpncpy(dst, src, n) + n;
+	(void)dst; (void)src; (void)n;
+	__libc_panic("unimplemented");
 }
 
 char *strdup(const char *s) {
@@ -115,15 +24,6 @@ char *strdup(const char *s) {
 	return buf;
 }
 
-size_t strnlen(const char *s, size_t len) {
-	for (size_t i = 0; i < len; i++) {
-		if (!s[i]) {
-			return i;
-		}
-	}
-	return len;
-}
-
 char *strsignal(int sig) {
 	static char buf[32];
 	snprintf(buf, sizeof(buf), "signal %d", sig);
diff --git a/src/libc/unistd.c b/src/libc/unistd.c
deleted file mode 100644
index e87cdb9..0000000
--- a/src/libc/unistd.c
+++ /dev/null
@@ -1,315 +0,0 @@
-#include <bits/panic.h>
-#include <camellia.h>
-#include <camellia/path.h>
-#include <camellia/syscalls.h>
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <elfload.h>
-
-int errno = 0;
-static char *_environ[] = {NULL};
-char **environ = _environ;
-
-int fork(void) {
-	return _sys_fork(0, NULL);
-}
-
-pid_t vfork(void) {
-	// TODO vfork is implemented improperly and will break stuff
-	return _sys_fork(0, NULL);
-}
-
-int close(hid_t h) {
-	return _sys_close(h);
-}
-
-_Noreturn void exit(int c) {
-	_sys_exit(c);
-}
-_Noreturn void _exit(int c) { exit(c); };
-
-ssize_t readlink(const char *restrict path, char *restrict buf, size_t bufsize) {
-	(void)path; (void)buf; (void)bufsize;
-	errno = ENOSYS;
-	return -1;
-}
-
-int link(const char *path1, const char *path2) {
-	(void)path1; (void)path2;
-	errno = ENOSYS;
-	return -1;
-}
-
-int unlink(const char *path) {
-	hid_t h = camellia_open(path, OPEN_WRITE);
-	if (h < 0) return errno = -h, -1;
-	long ret = _sys_remove(h);
-	if (ret < 0) return errno = -ret, -1;
-	return 0;
-}
-
-int rmdir(const char *path) {
-	(void)path;
-	__libc_panic("unimplemented");
-}
-
-int symlink(const char *path1, const char *path2) {
-	(void)path1; (void)path2;
-	errno = ENOSYS;
-	return -1;
-}
-
-// TODO isatty
-int isatty(int fd) {
-	return fd <= 2 ? 1 : 0;
-}
-
-
-int execv(const char *path, char *const argv[]) {
-	return execve(path, argv, NULL);
-}
-
-int execvp(const char *path, char *const argv[]) {
-	// TODO execvp
-	return execve(path, argv, NULL);
-}
-
-int execvpe(const char *path, char *const argv[], char *const envp[]) {
-	if (path[0] != '/') {
-		char *exp = malloc(strlen(path) + 6);
-		int ret;
-		strcpy(exp, "/bin/");
-		strcat(exp, path);
-		ret = execve(exp, argv, envp);
-		free(exp);
-		return ret;
-	}
-	return execve(path, argv, envp);
-}
-
-int execve(const char *path, char *const argv[], char *const envp[]) {
-	FILE *file = fopen(path, "e");
-	char hdr[4] = {0};
-	if (!file)
-		return -1;
-
-	fread(hdr, 1, 4, file);
-	fseek(file, 0, SEEK_SET);
-
-	if (!memcmp("\x7f""ELF", hdr, 4)) {
-		elf_execf(file, (void*)argv, (void*)envp);
-		fclose(file);
-	} else if (!memcmp("#!", hdr, 2)) {
-		char buf[256];
-		fseek(file, 2, SEEK_SET);
-		if (fgets(buf, sizeof buf, file)) {
-			const char *argv [] = {buf, path, NULL};
-			char *endl = strchr(buf, '\n');
-			if (endl) *endl = '\0';
-			execve(buf, (void*)argv, envp);
-		}
-	}
-
-	errno = EINVAL;
-	return -1;
-}
-
-
-static const char *__initialcwd;
-static char *cwd = NULL, *cwd2 = NULL;
-static size_t cwdcapacity = 0;
-
-static const char *getrealcwd(void) {
-	/* __initialcwd can't just be initialized with "/" because ld has seemingly
-	 * started to revolt against humanity and not process half the relocations
-	 * it sees. */
-	if (cwd) return cwd;
-	if (__initialcwd) return __initialcwd;
-	return "/";
-}
-
-int chdir(const char *path) {
-	hid_t h;
-	char *tmp;
-	size_t len = absolutepath(NULL, path, 0) + 1; /* +1 for the trailing slash */
-	if (cwdcapacity < len) {
-		cwdcapacity = len;
-		if (cwd) {
-			cwd = realloc(cwd, len);
-			cwd2 = realloc(cwd2, len);
-		} else {
-			size_t initlen = strlen(__initialcwd) + 1;
-			if (len < initlen)
-				len = initlen;
-			cwd = malloc(initlen);
-			cwd2 = malloc(initlen);
-			memcpy(cwd, __initialcwd, initlen);
-		}
-	}
-	absolutepath(cwd2, path, cwdcapacity);
-	len = strlen(cwd2);
-	if (cwd2[len - 1] != '/') {
-		cwd2[len] = '/';
-		cwd2[len + 1] = '\0';
-	}
-
-	/* check if exists */
-	h = camellia_open(cwd2, OPEN_READ);
-	if (h < 0) return errno = ENOENT, -1;
-	close(h);
-
-	tmp  = cwd;
-	cwd  = cwd2;
-	cwd2 = tmp;
-	return 0;
-}
-
-char *getcwd(char *buf, size_t capacity) {
-	const char *realcwd = getrealcwd();
-	size_t len = strlen(realcwd) + 1;
-	if (capacity < len) {
-		errno = capacity == 0 ? EINVAL : ERANGE;
-		return NULL;
-	}
-	memcpy(buf, realcwd, len);
-	return buf;
-}
-
-uid_t getuid(void) { return 0; }
-uid_t geteuid(void) { return 0; }
-gid_t getgid(void) { return 0; }
-gid_t getegid(void) { return 0; }
-
-int access(const char *path, int mode) {
-	// TODO impl access()
-	(void)path; (void)mode;
-	return 0;
-}
-
-int chown(const char *path, uid_t owner, gid_t group) {
-	(void)path; (void)owner; (void)group;
-	errno = ENOSYS;
-	return -1;
-}
-
-int setpgid(pid_t pid, pid_t pgid) {
-	(void)pid; (void)pgid;
-	return errno = ENOSYS, -1;
-}
-
-pid_t tcgetpgrp(int fd) {
-	(void)fd;
-	return errno = ENOSYS, -1;
-}
-
-int tcsetpgrp(int fd, pid_t pgrp) {
-	(void)fd; (void)pgrp;
-	return errno = ENOSYS, -1;
-}
-
-pid_t getpgrp(void) {
-	__libc_panic("unimplemented");
-}
-
-pid_t getpid(void) {
-	return _sys_getpid();
-}
-
-pid_t getppid(void) {
-	return _sys_getppid();
-}
-
-int getgroups(int size, gid_t list[]) {
-	(void)size; (void)list;
-	__libc_panic("unimplemented");
-}
-
-ssize_t read(int fd, void *buf, size_t count) {
-	// TODO real file descriptor emulation - store offsets
-	return _sys_read(fd, buf, count, -1);
-}
-
-ssize_t write(int fd, const void *buf, size_t count) {
-	// TODO real file descriptor emulation - store offsets
-	return _sys_write(fd, buf, count, -1, 0);
-}
-
-int pipe(int pipefd[2]) {
-	// TODO pipe buffering
-	int ret = _sys_pipe(pipefd, 0);
-	if (ret < 0) {
-		errno = -ret;
-		return -1;
-	}
-	return 0;
-}
-
-int dup(int oldfd) {
-	(void)oldfd;
-	__libc_panic("unimplemented");
-}
-
-int dup2(int oldfd, int newfd) {
-	int ret = _sys_dup(oldfd, newfd, 0);
-	if (ret < 0) {
-		errno = -ret;
-		ret = -1;
-	}
-	return ret;
-}
-
-unsigned int sleep(unsigned int seconds) {
-	_sys_sleep(seconds * 1000);
-	return 0;
-}
-
-size_t absolutepath(char *out, const char *in, size_t size) {
-	const char *realcwd = getrealcwd();
-	size_t len, pos = 0;
-	if (!in) return strlen(realcwd) + 1;
-
-	if (!(in[0] == '/')) {
-		len = strlen(realcwd);
-		if (pos + len <= size && out != realcwd)
-			memcpy(out + pos, realcwd, len);
-		pos += len;
-
-		if (realcwd[len - 1] != '/') {
-			if (pos + 1 <= size) out[pos] = '/';
-			pos++;
-		}
-	}
-
-	len = strlen(in);
-	if (pos + len <= size)
-		memcpy(out + pos, in, len);
-	pos += len;
-
-	if (pos <= size) {
-		pos = path_simplify(out, out, pos);
-		if (pos == 0) return 0;
-	}
-
-	if (pos + 1 <= size) out[pos] = '\0';
-	pos++;
-
-	return pos;
-}
-
-void __setinitialcwd(const char *s) {
-	__initialcwd = s;
-}
-
-static void intr_null(void) { }
-
-extern void (*volatile _intr)(void);
-void intr_set(void (*fn)(void)) {
-	_intr = fn ? fn : intr_null;
-}
-
-void intr_default(void) {
-	exit(-1);
-}
diff --git a/src/libc/unistd/cwd.c b/src/libc/unistd/cwd.c
new file mode 100644
index 0000000..7689d56
--- /dev/null
+++ b/src/libc/unistd/cwd.c
@@ -0,0 +1,95 @@
+#include <camellia.h>
+#include <camellia/path.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+static char *cwd = NULL, *cwd2 = NULL;
+static size_t cwdcapacity = 0;
+
+static const char *getrealcwd(void) {
+	if (cwd) return cwd;
+	if (__initialcwd) return __initialcwd;
+	return "/";
+}
+
+int chdir(const char *path) {
+	hid_t h;
+	char *tmp;
+	size_t len = absolutepath(NULL, path, 0) + 1; /* +1 for the trailing slash */
+	if (cwdcapacity < len) {
+		cwdcapacity = len;
+		if (cwd) {
+			cwd = realloc(cwd, len);
+			cwd2 = realloc(cwd2, len);
+		} else {
+			size_t initlen = strlen(__initialcwd) + 1;
+			if (len < initlen)
+				len = initlen;
+			cwd = malloc(initlen);
+			cwd2 = malloc(initlen);
+			memcpy(cwd, __initialcwd, initlen);
+		}
+	}
+	absolutepath(cwd2, path, cwdcapacity);
+	len = strlen(cwd2);
+	if (cwd2[len - 1] != '/') {
+		cwd2[len] = '/';
+		cwd2[len + 1] = '\0';
+	}
+
+	/* check if exists */
+	h = camellia_open(cwd2, OPEN_READ);
+	if (h < 0) return errno = ENOENT, -1;
+	close(h);
+
+	tmp  = cwd;
+	cwd  = cwd2;
+	cwd2 = tmp;
+	return 0;
+}
+
+char *getcwd(char *buf, size_t capacity) {
+	const char *realcwd = getrealcwd();
+	size_t len = strlen(realcwd) + 1;
+	if (capacity < len) {
+		errno = capacity == 0 ? EINVAL : ERANGE;
+		return NULL;
+	}
+	memcpy(buf, realcwd, len);
+	return buf;
+}
+
+size_t absolutepath(char *out, const char *in, size_t size) {
+	const char *realcwd = getrealcwd();
+	size_t len, pos = 0;
+	if (!in) return strlen(realcwd) + 1;
+
+	if (!(in[0] == '/')) {
+		len = strlen(realcwd);
+		if (pos + len <= size && out != realcwd)
+			memcpy(out + pos, realcwd, len);
+		pos += len;
+
+		if (realcwd[len - 1] != '/') {
+			if (pos + 1 <= size) out[pos] = '/';
+			pos++;
+		}
+	}
+
+	len = strlen(in);
+	if (pos + len <= size)
+		memcpy(out + pos, in, len);
+	pos += len;
+
+	if (pos <= size) {
+		pos = path_simplify(out, out, pos);
+		if (pos == 0) return 0;
+	}
+
+	if (pos + 1 <= size) out[pos] = '\0';
+	pos++;
+
+	return pos;
+}
diff --git a/src/libc/unistd/simple.c b/src/libc/unistd/simple.c
new file mode 100644
index 0000000..911c974
--- /dev/null
+++ b/src/libc/unistd/simple.c
@@ -0,0 +1,128 @@
+/** Functions from unistd.h that are either just a syscall or a return. */
+
+#include <camellia/syscalls.h>
+#include <errno.h>
+#include <unistd.h>
+
+int errno = 0;
+static char *_environ[] = {NULL};
+char **environ = _environ;
+const char *__initialcwd = NULL;
+
+int fork(void) {
+	return _sys_fork(0, NULL);
+}
+
+pid_t vfork(void) {
+	// TODO vfork is implemented improperly and will break stuff
+	return _sys_fork(0, NULL);
+}
+
+int close(hid_t h) {
+	return _sys_close(h);
+}
+
+_Noreturn void exit(int c) {
+	_sys_exit(c);
+}
+_Noreturn void _exit(int c) {
+	exit(c);
+};
+
+ssize_t readlink(const char *restrict path, char *restrict buf, size_t bufsize) {
+	(void)path; (void)buf; (void)bufsize;
+	errno = ENOSYS;
+	return -1;
+}
+
+int link(const char *path1, const char *path2) {
+	(void)path1; (void)path2;
+	errno = ENOSYS;
+	return -1;
+}
+
+int symlink(const char *path1, const char *path2) {
+	(void)path1; (void)path2;
+	errno = ENOSYS;
+	return -1;
+}
+
+// TODO isatty
+int isatty(int fd) {
+	return fd <= 2 ? 1 : 0;
+}
+
+uid_t getuid(void) { return 0; }
+uid_t geteuid(void) { return 0; }
+gid_t getgid(void) { return 0; }
+gid_t getegid(void) { return 0; }
+
+int access(const char *path, int mode) {
+	// TODO impl access()
+	(void)path; (void)mode;
+	return 0;
+}
+
+int chown(const char *path, uid_t owner, gid_t group) {
+	(void)path; (void)owner; (void)group;
+	errno = ENOSYS;
+	return -1;
+}
+
+int setpgid(pid_t pid, pid_t pgid) {
+	(void)pid; (void)pgid;
+	return errno = ENOSYS, -1;
+}
+
+pid_t tcgetpgrp(int fd) {
+	(void)fd;
+	return errno = ENOSYS, -1;
+}
+
+int tcsetpgrp(int fd, pid_t pgrp) {
+	(void)fd; (void)pgrp;
+	return errno = ENOSYS, -1;
+}
+
+pid_t getpid(void) {
+	return _sys_getpid();
+}
+
+pid_t getppid(void) {
+	return _sys_getppid();
+}
+
+ssize_t read(int fd, void *buf, size_t count) {
+	// TODO real file descriptor emulation - store offsets
+	// TODO errno
+	return _sys_read(fd, buf, count, -1);
+}
+
+ssize_t write(int fd, const void *buf, size_t count) {
+	// TODO real file descriptor emulation - store offsets
+	return _sys_write(fd, buf, count, -1, 0);
+}
+
+int pipe(int pipefd[2]) {
+	// TODO pipe buffering
+	int ret = _sys_pipe(pipefd, 0);
+	if (ret < 0) {
+		errno = -ret;
+		return -1;
+	}
+	return 0;
+}
+
+int dup2(int oldfd, int newfd) {
+	int ret = _sys_dup(oldfd, newfd, 0);
+	if (ret < 0) {
+		errno = -ret;
+		ret = -1;
+	}
+	return ret;
+}
+
+unsigned int sleep(unsigned int seconds) {
+	_sys_sleep(seconds * 1000);
+	return 0;
+}
diff --git a/src/libc/unistd/unistd.c b/src/libc/unistd/unistd.c
new file mode 100644
index 0000000..102e72a
--- /dev/null
+++ b/src/libc/unistd/unistd.c
@@ -0,0 +1,85 @@
+#include <bits/panic.h>
+#include <camellia.h>
+#include <camellia/syscalls.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <elfload.h>
+
+int unlink(const char *path) {
+	hid_t h = camellia_open(path, OPEN_WRITE);
+	if (h < 0) return errno = -h, -1;
+	long ret = _sys_remove(h);
+	if (ret < 0) return errno = -ret, -1;
+	return 0;
+}
+
+int rmdir(const char *path) {
+	(void)path;
+	__libc_panic("unimplemented");
+}
+
+int execv(const char *path, char *const argv[]) {
+	return execve(path, argv, NULL);
+}
+
+int execvp(const char *path, char *const argv[]) {
+	// TODO execvp
+	return execve(path, argv, NULL);
+}
+
+int execvpe(const char *path, char *const argv[], char *const envp[]) {
+	if (path[0] != '/') {
+		char *exp = malloc(strlen(path) + 6);
+		int ret;
+		strcpy(exp, "/bin/");
+		strcat(exp, path);
+		ret = execve(exp, argv, envp);
+		free(exp);
+		return ret;
+	}
+	return execve(path, argv, envp);
+}
+
+int execve(const char *path, char *const argv[], char *const envp[]) {
+	FILE *file = fopen(path, "e");
+	char hdr[4] = {0};
+	if (!file)
+		return -1;
+
+	fread(hdr, 1, 4, file);
+	fseek(file, 0, SEEK_SET);
+
+	if (!memcmp("\x7f""ELF", hdr, 4)) {
+		elf_execf(file, (void*)argv, (void*)envp);
+		fclose(file);
+	} else if (!memcmp("#!", hdr, 2)) {
+		char buf[256];
+		fseek(file, 2, SEEK_SET);
+		if (fgets(buf, sizeof buf, file)) {
+			const char *argv [] = {buf, path, NULL};
+			char *endl = strchr(buf, '\n');
+			if (endl) *endl = '\0';
+			execve(buf, (void*)argv, envp);
+		}
+	}
+
+	errno = EINVAL;
+	return -1;
+}
+
+pid_t getpgrp(void) {
+	__libc_panic("unimplemented");
+}
+
+int getgroups(int size, gid_t list[]) {
+	(void)size; (void)list;
+	__libc_panic("unimplemented");
+}
+
+int dup(int oldfd) {
+	(void)oldfd;
+	__libc_panic("unimplemented");
+}