add more string.h functions

include/string.h

@@ -3,21 +3,41 @@
 #include <stddef.h>  // size_t
 
 size_t strlen(const char *s);
+size_t strnlen(const char *s, size_t n);
+
 char *strchr(const char *s, int c);
 char *strrchr(const char *s, int c);
 char *strstr(const char *s1, const char *s2);
+
 int strcmp(const char *p, const char *q);
 int strncmp(const char *p, const char *q, size_t n);
+int strcoll(const char *p, const char *q);
+
 char *strcpy(char *dst, const char *src);
 char *strncpy(char *dst, const char *src, size_t n);
+
+char *stpcpy(char *dst, const char *src);
+char *stpncpy(char *dst, const char *src, size_t n);
+
 char *strcat(char *dst, const char *src);
 char *strncat(char *dst, const char *src, size_t n);
 
 char *strdup(const char *str);
 char *strndup(const char *str, size_t size);
 
 void *memcpy(void *dst, const void *src, size_t n);
+void *memccpy(void *dst, const void *src, int c, size_t n);
 void *memmove(void *dst, const void *src, size_t);
 void *memset(void *buf, int val, size_t size);
 void *memchr(const void *buf, int c, size_t n);
 int memcmp(const void *buf1, const void *buf2, size_t n);
+
+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 *strerror(int no);
+int strerror_r(int no, char *dst, size_t n);
+
+char *strtok(char *src, const char *delim);
+char *strtok_r(char *src, const char *delim, char **ptr);

libsrc/stdio/perror.c

@@ -1,5 +1,10 @@
 #include "stdio.h"
+#include "string.h"
+#include "errno.h"
 
 void perror(const char *msg) {
-  fprintf(stderr, "perror: %s\n", msg);
+  int no = errno;
+  if (msg != NULL && *msg != '\0')
+    fprintf(stderr, "%s: ", msg);
+  fprintf(stderr, "%s\n", strerror(no));
 }

libsrc/string/memccpy.c

@@ -0,0 +1,8 @@
+#include "string.h"
+
+void *memccpy(void *dst, const void *src, int c, size_t n) {
+  char *b = memchr(src, c, n);
+  if (b != NULL)
+    n = b - (char *)src;
+  return memcpy(dst, src, n);
+}

libsrc/string/stpcpy.c

@@ -0,0 +1,7 @@
+#include "string.h"
+
+char *stpcpy(char *dst, const char *src) {
+  while ((*dst++ = *src++) != '\0')
+    ;
+  return dst;
+}

libsrc/string/stpncpy.c

@@ -0,0 +1,7 @@
+#include "string.h"
+
+char *stpncpy(char *dst, const char *src, size_t n) {
+  for (; n > 0 && (*dst++ = *src++) != '\0'; --n)
+    ;
+  return dst;
+}

libsrc/string/strcoll.c

@@ -0,0 +1,5 @@
+#include "string.h"
+
+int strcoll(const char *p, const char *q) {
+  return strcmp(p, q);
+}

libsrc/string/strcspn.c

@@ -0,0 +1,8 @@
+#include "string.h"
+
+size_t strcspn(const char *s, const char *reject) {
+  size_t n;
+  for (n = 0; s[n] != '\0' && strchr(reject, s[n]) == NULL; ++n)
+    ;
+  return n;
+}

libsrc/string/strerror.c

@@ -0,0 +1,45 @@
+#include "string.h"
+
+static char *strerrors[] = {
+  "Success",
+  "Operation not permitted",
+  "No such file or directory",
+  "No such process",
+  "Interrupted system call",
+  "I/O error",
+  "No such device or address",
+  "Argument list too long",
+  "Exec format error",
+  "Bad file number",
+  "No child processes",
+  "Try again",
+  "Out of memory",
+  "Permission denied",
+  "Bad address",
+  "Block device required",
+  "Device or resource busy",
+  "File exists",
+  "Cross-device link",
+  "No such device",
+  "Not a directory",
+  "Is a directory",
+  "Invalid argument",
+  "File table overflow",
+  "Too many open files",
+  "Not a typewriter",
+  "Text file busy",
+  "File too large",
+  "No space left on device",
+  "Illegal seek",
+  "Read-only file system",
+  "Too many links",
+  "Broken pipe",
+  "Math argument out of domain of func",
+  "Math result not representable",
+};
+
+char *strerror(int no) {
+  if (no < 0 || no >= sizeof(strerrors) / sizeof(*strerrors))
+    return "Unknown error";
+  return strerrors[no];
+}

libsrc/string/strerror_r.c

@@ -0,0 +1,6 @@
+#include "string.h"
+
+int strerror_r(int no, char *dst, size_t n) {
+  strncpy(dst, strerror(no), n);
+  return 0;
+}

libsrc/string/strnlen.c

@@ -0,0 +1,8 @@
+#include "string.h"
+
+size_t strnlen(const char *s, size_t n) {
+  size_t len;
+  for (len = 0; len < n && s[len] != '\0'; ++len)
+    ;
+  return len;
+}

libsrc/string/strpbrk.c

@@ -0,0 +1,8 @@
+#include "string.h"
+
+char *strpbrk(const char *s, const char *accept) {
+  const char *r = s + strcspn(s, accept);
+  if (*r == '\0')
+    return NULL;
+  return (char *)r;
+}

libsrc/string/strspn.c

@@ -0,0 +1,8 @@
+#include "string.h"
+
+size_t strspn(const char *s, const char *accept) {
+  size_t n;
+  for (n = 0; s[n] != '\0' && strchr(accept, s[n]) != NULL; ++n)
+    ;
+  return n;
+}

libsrc/string/strtok.c

@@ -0,0 +1,6 @@
+#include "string.h"
+
+char *strtok(char *src, const char *delim) {
+  static char *ptr;
+  return strtok_r(src, delim, &ptr);
+}

libsrc/string/strtok_r.c

@@ -0,0 +1,14 @@
+#include "string.h"
+
+char *strtok_r(char *src, const char *delim, char **ptr) {
+  if (src != NULL)
+    *ptr = src;
+  *ptr += strspn(*ptr, delim);
+  if (**ptr == '\0')
+    return NULL;
+  char *r = *ptr;
+  size_t n = strcspn(r, delim);
+  r[n] = '\0';
+  *ptr += n + 1;
+  return r;
+}