/* wrapper/rvs.c -- general and machine specific functions for rvs.
   system depends:<stdio.h> <stdlib.h> <string.h> <unistd.h> <errno.h> <error.h>
   Copyright (C) 2009 Luke Shumaker
   
   This file is part of rvs.
   
   rvs 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 2, or (at your
   option) any later version.
   
   rvs 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 rvs; see the file COPYING.
   If not, write to the Free Software Foundation,
   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <error.h>

#include "rvs.h"

void *
xmalloc (size_t size)
{
	void *value = malloc (size);
	if (value == NULL) {
		perror(program_invocation_name);
		exit(EXIT_FAILURE);
	}
	return value;
}

void *
xrealloc (void *ptr, size_t size)
{
	void *value = realloc (ptr, size);
	if (value == NULL) {
		perror(program_invocation_name);
		exit(EXIT_FAILURE);
	}
	return value;
}

void
xfree (void *ptr)
{
	if (ptr!=NULL)
		free (ptr);
}

void
xsystem (const char *command)
{
	int stat=system(command);
	if (stat!=0) {
		if (stat==-1) {
			fprintf(stderr,
				"%s: unable to launch run command",
				program_invocation_name);
			exit(EXIT_FAILURE);
		} else
			exit(EXIT_FAILURE);
	}
}

/* unistd.h */
int
xchdir (const char *filename)
{
	int ret=chdir(filename);
	if (ret != 0)
		error(EXIT_FAILURE,errno,"%s/",filename);
	return ret;
}

/* stdio.h */
FILE *
xfopen (const char *filename, const char *opentype)
{
	FILE *file = fopen(filename,opentype);
	/* fopen gives NULL on failure */
	if ( file == NULL )
		error(EXIT_FAILURE,errno,"%s",filename);
	return file;
}

/* string funtions */
void
stradds(size_t *size, char **dest, char *str)
{
	if (*size > ( strlen(*dest) + strlen(str) ))
		strcat(*dest, str);
	else {
		*size = strlen(*dest) + strlen(str) + 1;
		*dest = (char *) xrealloc (*dest, *size);
		strcat(*dest, str);
	}
}

char *
stralloc (const char *string)
{
	char *copy = (char *)xmalloc(strlen(string)+1);
	strcpy(copy,string);
	return copy;
}