Add stresep(3).

libc/Makefile

@@ -210,6 +210,7 @@ string/strdup.o \
 string/strerror_l.o \
 string/strerror.o \
 string/strerror_r.o \
+string/stresep.o \
 string/strlcat.o \
 string/strlcpy.o \
 string/strlen.o \

libc/include/string.h

@@ -129,6 +129,7 @@ int ffsl(long int);
 void* memrchr(const void*, int, size_t);
 /* TODO: strcasecmp_l */
 char* strchrnul(const char* str, int c);
+char* stresep(char**, const char*, int);
 size_t strlcat(char* __restrict, const char* __restrict, size_t);
 size_t strlcpy(char* __restrict, const char* __restrict, size_t);
 /* TODO: strncasecmp_l */

libc/string/stresep.cpp

@@ -0,0 +1,63 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2014.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix 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 Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    string/stresep.cpp
+    Extract a token from a string while handling escape characters.
+
+*******************************************************************************/
+
+#include <string.h>
+
+extern "C" char* stresep(char** string_ptr, const char* delim, int escape)
+{
+	char* token = *string_ptr;
+	if ( !token )
+		return NULL;
+	size_t consumed_length = 0;
+	size_t token_length = 0;
+	bool escaped = false;
+	while ( true )
+	{
+		char c = token[consumed_length++];
+		bool true_nul = c == '\0';
+		if ( !escaped && escape && (unsigned char) c == (unsigned char) escape )
+		{
+			escaped = true;
+			continue;
+		}
+		if ( !escaped && c != '\0' )
+		{
+			for ( size_t i = 0; delim[i]; i++ )
+			{
+				if ( c != delim[i] )
+				{
+					c = '\0';
+					break;
+				}
+			}
+		}
+		token[token_length++] = c;
+		escaped = false;
+		if ( c == '\0' )
+		{
+			*string_ptr = true_nul ? (char*) NULL : token + consumed_length;
+			return token;
+		}
+	}
+}