add string/array comparision functions

Signed-off-by: Mattias Andrée <maandree@operamail.com>

7 files changed, 427 insertions, 2 deletions

diff --git a/TODO b/TODO
index 4a7fd7a..b98ef49 100644
--- a/TODO
+++ b/TODO
@@ -1,6 +1,5 @@
 functions to lock and unlock pages  (3.4.3 p76)
 character class determination for wide characters  (4.3 p82)
-string/array comparison  (5.5 p105)
 collation functions  (5.6 p109)
 search functions  (5.7 p114)
 finding tokens in a string  (5.8 p119)
diff --git a/include/string.h b/include/string.h
index 0a41899..604fe1a 100644
--- a/include/string.h
+++ b/include/string.h
@@ -116,6 +116,7 @@ char* __gnu_strerror_r(int, char*, size_t); /* GNU-specific strerror_r */
 #endif
 
 
+
 /**
  * Returns the number of bytes in a NUL-terminated
  * string. This excludes the NUL byte.
@@ -705,5 +706,48 @@ void* memdup(const void*, size_t)
 
 
 
+/**
+ * Compare two memory segments alphabetically in a case sensitive manner.
+ * 
+ * @param   a     A negetive value is returned if this is the lesser.
+ * @param   b     A positive value is returned if this is the lesser.
+ * @param   size  The size of the segments.
+ * @return        Zero is returned if `a` and `b` are equal, otherwise,
+ *                see the specifications for `a` and `b`.
+ */
+int memcmp(const void*, const void*, size_t)
+  __GCC_ONLY(__attribute__((warn_unused_result)));
+
+/**
+ * Compare two strings alphabetically in a case sensitive manner.
+ * 
+ * @param   a  A negetive value is returned if this is the lesser.
+ * @param   b  A positive value is returned if this is the lesser.
+ * @return     Zero is returned if `a` and `b` are equal, otherwise,
+ *             see the specifications for `a` and `b`.
+ */
+int strcmp(const char*, const char*)
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+
+/**
+ * Compare two strings alphabetically in a case sensitive manner.
+ * 
+ * @param   a       A negetive value is returned if this is the lesser.
+ * @param   b       A positive value is returned if this is the lesser.
+ * @param   length  The maximum number of characters to compare.
+ * @return          Zero is returned if `a` and `b` are equal, otherwise,
+ *                  see the specifications for `a` and `b`.
+ */
+int strncmp(const char*, const char*, size_t)
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+
+
+#if defined(_GNU_SOURCE) && !defined(__PORTABLE)
+int strverscmp(const char*, const char*)
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull))); /* TODO document and implement strverscmp */
+#end if
+
+
+
 #endif
 
diff --git a/include/strings.h b/include/strings.h
index 0a4bc5e..15b8b1a 100644
--- a/include/strings.h
+++ b/include/strings.h
@@ -23,7 +23,6 @@
 
 
 #define __NEED_size_t
-
 #include <bits/types.h>
 
 
@@ -60,6 +59,41 @@ void explicit_bzero(void*, size_t);
 void bcopy(const void*, void*, size_t)
   __deprecated("Use 'memmove', or similar function, instead, but be aware of reordered paramters.");
 
+/**
+ * This function is identical to `memcmp`.
+ */
+int bcmp(const void*, const void*, size_t)
+  __deprecated("Use 'memcmp' instead.")
+  __GCC_ONLY(__attribute__((warn_unused_result)));
+
+
+/**
+ * Compare two strings alphabetically in a case insensitive manner.
+ * Be aware, only ASCII characters are case insensitive, non-ASCII
+ * characters are case sensitive.
+ * 
+ * @param   a  A negetive value is returned if this is the lesser.
+ * @param   b  A positive value is returned if this is the lesser.
+ * @return     Zero is returned if `a` and `b` are equal, otherwise,
+ *             see the specifications for `a` and `b`.
+ */
+int strcasecmp(const char*, const char*)
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+
+/**
+ * Compare two strings alphabetically in a case insensitive manner.
+ * Be aware, only ASCII characters are case insensitive, non-ASCII
+ * characters are case sensitive.
+ * 
+ * @param   a       A negetive value is returned if this is the lesser.
+ * @param   b       A positive value is returned if this is the lesser.
+ * @param   length  The maximum number of characters to compare.
+ * @return          Zero is returned if `a` and `b` are equal, otherwise,
+ *                  see the specifications for `a` and `b`.
+ */
+int strncasecmp(const char*, const char*, size_t)
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+
 
 
 #endif
diff --git a/include/wchar.h b/include/wchar.h
index 34c066e..1b44690 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -631,6 +631,78 @@ wchar_t* wmemdup(const wchar_t*, size_t)
 
 
 
+/**
+ * Compare two memory segments alphabetically in a case sensitive manner.
+ * 
+ * @param   a     A negetive value is returned if this is the lesser.
+ * @param   b     A positive value is returned if this is the lesser.
+ * @param   size  The size of the segments.
+ * @return        Zero is returned if `a` and `b` are equal, otherwise,
+ *                see the specifications for `a` and `b`.
+ */
+int wmemcmp(const wchar_t*, const wchar_t*, size_t)
+  __GCC_ONLY(__attribute__((warn_unused_result)));
+
+/**
+ * Compare two strings alphabetically in a case sensitive manner.
+ * 
+ * @param   a  A negetive value is returned if this is the lesser.
+ * @param   b  A positive value is returned if this is the lesser.
+ * @return     Zero is returned if `a` and `b` are equal, otherwise,
+ *             see the specifications for `a` and `b`.
+ */
+int wcscmp(const wchar_t*, const wchar_t*)
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+
+#if (defined(_GNU_SOURCE) || defined(_SLIBC_SOURCE)) && !defined(__PORTABLE)
+/**
+ * Compare two strings alphabetically in a case insensitive manner.
+ * Be aware, only ASCII characters are case insensitive, non-ASCII
+ * characters are case sensitive.
+ * 
+ * This is a GNU-compliant slibc extension.
+ * 
+ * @param   a  A negetive value is returned if this is the lesser.
+ * @param   b  A positive value is returned if this is the lesser.
+ * @return     Zero is returned if `a` and `b` are equal, otherwise,
+ *             see the specifications for `a` and `b`.
+ */
+int wcscasecmp(const wchar_t*, const wchar_t*)
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+
+/**
+ * Compare two strings alphabetically in a case sensitive manner.
+ * 
+ * This is a GNU-compliant slibc extension.
+ * 
+ * @param   a       A negetive value is returned if this is the lesser.
+ * @param   b       A positive value is returned if this is the lesser.
+ * @param   length  The maximum number of characters to compare.
+ * @return          Zero is returned if `a` and `b` are equal, otherwise,
+ *                  see the specifications for `a` and `b`.
+ */
+int wcsncmp(const wchar_t*, const wchar_t*, size_t)
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+
+/**
+ * Compare two strings alphabetically in a case insensitive manner.
+ * Be aware, only ASCII characters are case insensitive, non-ASCII
+ * characters are case sensitive.
+ * 
+ * This is a GNU-compliant slibc extension.
+ * 
+ * @param   a       A negetive value is returned if this is the lesser.
+ * @param   b       A positive value is returned if this is the lesser.
+ * @param   length  The maximum number of characters to compare.
+ * @return          Zero is returned if `a` and `b` are equal, otherwise,
+ *                  see the specifications for `a` and `b`.
+ */
+int wcsncasecmp(const wchar_t*, const wchar_t*, size_t)
+  __GCC_ONLY(__attribute__((warn_unused_result, nonnull)));
+#endif
+
+
+
 #endif
 #endif
 
diff --git a/src/string/strcmp.c b/src/string/strcmp.c
new file mode 100644
index 0000000..966bb06
--- /dev/null
+++ b/src/string/strcmp.c
@@ -0,0 +1,122 @@
+/**
+ * slibc — Yet another C library
+ * Copyright © 2015  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program 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.
+ * 
+ * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <string.h>
+#include <strings.h>
+#include <stddef.h>
+#include <inttypes.h>
+#include <ctype.h>
+
+
+
+/**
+ * Compare two memory segments alphabetically in a case sensitive manner.
+ * 
+ * @param   a     A negetive value is returned if this is the lesser.
+ * @param   b     A positive value is returned if this is the lesser.
+ * @param   size  The size of the segments.
+ * @return        Zero is returned if `a` and `b` are equal, otherwise,
+ *                see the specifications for `a` and `b`.
+ */
+int memcmp(const void* a, const void* b, size_t size)
+{
+  const signed char* s1 = a;
+  const signed char* s2 = b;
+  while (size--)
+    if (*s1 == *s2)
+      s1++, s2++;
+    else
+      return (int)(*s1 - *s2);
+  return 0;
+}
+
+
+/**
+ * Compare two strings alphabetically in a case sensitive manner.
+ * 
+ * @param   a  A negetive value is returned if this is the lesser.
+ * @param   b  A positive value is returned if this is the lesser.
+ * @return     Zero is returned if `a` and `b` are equal, otherwise,
+ *             see the specifications for `a` and `b`.
+ */
+int strcmp(const char* a, const char* b)
+{
+  size_t n = strlen(a);
+  size_t m = strlen(b);
+  return memcmp(a, b, (n < m ? n : m) + 1);
+}
+
+
+/**
+ * Compare two strings alphabetically in a case insensitive manner.
+ * Be aware, only ASCII characters are case insensitive, non-ASCII
+ * characters are case sensitive.
+ * 
+ * @param   a  A negetive value is returned if this is the lesser.
+ * @param   b  A positive value is returned if this is the lesser.
+ * @return     Zero is returned if `a` and `b` are equal, otherwise,
+ *             see the specifications for `a` and `b`.
+ */
+int strcasecmp(const char* a, const char* b)
+{
+  return strncasecmp(a, b, SIZE_MAX);
+}
+
+
+/**
+ * Compare two strings alphabetically in a case sensitive manner.
+ * 
+ * @param   a       A negetive value is returned if this is the lesser.
+ * @param   b       A positive value is returned if this is the lesser.
+ * @param   length  The maximum number of characters to compare.
+ * @return          Zero is returned if `a` and `b` are equal, otherwise,
+ *                  see the specifications for `a` and `b`.
+ */
+int strncmp(const char* a, const char* b, size_t length)
+{
+  size_t n = strnlen(a, length);
+  size_t m = strnlen(b, length);
+  int r = memcmp(a, b, (n < m ? n : m));
+  return r ? r : n == m ? 0 : n < m ? -1 : +1;
+}
+
+
+/**
+ * Compare two strings alphabetically in a case insensitive manner.
+ * Be aware, only ASCII characters are case insensitive, non-ASCII
+ * characters are case sensitive.
+ * 
+ * @param   a       A negetive value is returned if this is the lesser.
+ * @param   b       A positive value is returned if this is the lesser.
+ * @param   length  The maximum number of characters to compare.
+ * @return          Zero is returned if `a` and `b` are equal, otherwise,
+ *                  see the specifications for `a` and `b`.
+ */
+int strncasecmp(const char* a, const char* b, size_t length)
+{
+  int c1, c2;
+  for (; size--; a++, b++)
+    if (*a != *b)
+      {
+	c1 = isalpha(*a) ? tolower(*a) : (int)*a;
+	c2 = isalpha(*b) ? tolower(*b) : (int)*b;
+	if ((c1 -= c2))
+	  return c1;
+      }
+  return 0;
+}
+
diff --git a/src/strings/bcmp.c b/src/strings/bcmp.c
new file mode 100644
index 0000000..10f0d00
--- /dev/null
+++ b/src/strings/bcmp.c
@@ -0,0 +1,29 @@
+/**
+ * slibc — Yet another C library
+ * Copyright © 2015  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program 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.
+ * 
+ * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <strings.h>
+#include <string.h>
+
+
+/**
+ * This function is identical to `memcmp`.
+ */
+int bcmp(const void* a, const void* b, size_t size)
+{
+  return memcmp(a, b, size);
+}
+
diff --git a/src/wchar/wcscmp.c b/src/wchar/wcscmp.c
new file mode 100644
index 0000000..ebac2df
--- /dev/null
+++ b/src/wchar/wcscmp.c
@@ -0,0 +1,125 @@
+/**
+ * slibc — Yet another C library
+ * Copyright © 2015  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program 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.
+ * 
+ * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <wchar.h>
+#include <stddef.h>
+#include <inttypes.h>
+#include <wctype.h>
+
+
+
+/**
+ * Compare two memory segments alphabetically in a case sensitive manner.
+ * 
+ * @param   a     A negetive value is returned if this is the lesser.
+ * @param   b     A positive value is returned if this is the lesser.
+ * @param   size  The size of the segments.
+ * @return        Zero is returned if `a` and `b` are equal, otherwise,
+ *                see the specifications for `a` and `b`.
+ */
+int wmemcmp(const wchar_t* a, const wchar_t* b, size_t size)
+{
+  while (size--)
+    if (*a == *b)
+      a++, b++;
+    else
+      return *a < *b ? -1 : +1;
+  return 0;
+}
+
+
+/**
+ * Compare two strings alphabetically in a case sensitive manner.
+ * 
+ * @param   a  A negetive value is returned if this is the lesser.
+ * @param   b  A positive value is returned if this is the lesser.
+ * @return     Zero is returned if `a` and `b` are equal, otherwise,
+ *             see the specifications for `a` and `b`.
+ */
+int wcscmp(const wchar_t* a, const wchar_t* b)
+{
+  size_t n = wcslen(a);
+  size_t m = wcslen(b);
+  return wmemcmp(a, b, (n < m ? n : m) + 1);
+}
+
+
+/**
+ * Compare two strings alphabetically in a case insensitive manner.
+ * Be aware, only ASCII characters are case insensitive, non-ASCII
+ * characters are case sensitive.
+ * 
+ * This is a GNU-compliant slibc extension.
+ * 
+ * @param   a  A negetive value is returned if this is the lesser.
+ * @param   b  A positive value is returned if this is the lesser.
+ * @return     Zero is returned if `a` and `b` are equal, otherwise,
+ *             see the specifications for `a` and `b`.
+ */
+int wcscasecmp(const wchar_t* a, const wchar_t* b)
+{
+  return wcsncasecmp(a, b, SIZE_MAX);
+}
+
+
+/**
+ * Compare two strings alphabetically in a case sensitive manner.
+ * 
+ * This is a GNU-compliant slibc extension.
+ * 
+ * @param   a       A negetive value is returned if this is the lesser.
+ * @param   b       A positive value is returned if this is the lesser.
+ * @param   length  The maximum number of characters to compare.
+ * @return          Zero is returned if `a` and `b` are equal, otherwise,
+ *                  see the specifications for `a` and `b`.
+ */
+int wcsncmp(const wchar_t* a, const wchar_t* b, size_t length)
+{
+  size_t n = wcsnlen(a, length);
+  size_t m = wcsnlen(b, length);
+  int r = wmemcmp(a, b, (n < m ? n : m));
+  return r ? r : n == m ? 0 : n < m ? -1 : +1
+}
+
+
+/**
+ * Compare two strings alphabetically in a case insensitive manner.
+ * Be aware, only ASCII characters are case insensitive, non-ASCII
+ * characters are case sensitive.
+ * 
+ * This is a GNU-compliant slibc extension.
+ * 
+ * @param   a       A negetive value is returned if this is the lesser.
+ * @param   b       A positive value is returned if this is the lesser.
+ * @param   length  The maximum number of characters to compare.
+ * @return          Zero is returned if `a` and `b` are equal, otherwise,
+ *                  see the specifications for `a` and `b`.
+ */
+int wcsncasecmp(const wchar_t* a, const wchar_t* b, size_t length)
+{
+  wchar_t c1, c2;
+  for (; size--; a++, b++)
+    if (*a != *b)
+      {
+	c1 = iswalpha(*a) ? towlower(*a) : *a;
+	c2 = iswalpha(*b) ? towlower(*b) : *b;
+	if (c1 < c2)  return -1;
+	if (c1 > c2)  return +1;
+      }
+  return 0;
+}
+