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/*
* helpers.h
* This is private to us and not for user consumption
*/
/*
* Copyright (c) 2007-2015 The OpenRC Authors.
* See the Authors file at the top-level directory of this distribution and
* https://github.com/OpenRC/openrc/blob/HEAD/AUTHORS
*
* This file is part of OpenRC. It is subject to the license terms in
* the LICENSE file found in the top-level directory of this
* distribution and at https://github.com/OpenRC/openrc/blob/HEAD/LICENSE
* This file may not be copied, modified, propagated, or distributed
* except according to the terms contained in the LICENSE file.
*/
#ifndef __HELPERS_H__
#define __HELPERS_H__
#include <stdarg.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include <fcntl.h>
#define ERRX do { fprintf (stderr, "out of memory\n"); exit (1); } while (0)
#define UNCONST(a) ((void *)(uintptr_t)(const void *)(a))
#define RC_UNUSED __attribute__((__unused__))
#define RC_NORETURN __attribute__((__noreturn__))
#define RC_PRINTF(a, b) __attribute__((__format__(__printf__, a, b)))
#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
#ifndef HAVE_STRLCPY
# define strlcpy(dst, src, size) snprintf(dst, size, "%s", src)
#endif
#ifndef timespecsub
#define timespecsub(tsp, usp, vsp) \
do { \
(vsp)->tv_sec = (tsp)->tv_sec - (usp)->tv_sec; \
(vsp)->tv_nsec = (tsp)->tv_nsec - (usp)->tv_nsec; \
if ((vsp)->tv_nsec < 0) { \
(vsp)->tv_sec--; \
(vsp)->tv_nsec += 1000000000L; \
} \
} while (/* CONSTCOND */ 0)
#endif
RC_UNUSED static void *xmalloc (size_t size)
{
void *value = malloc(size);
if (value)
return (value);
ERRX;
/* NOTREACHED */
}
RC_UNUSED static void *xrealloc(void *ptr, size_t size)
{
void *value = realloc(ptr, size);
if (value)
return (value);
ERRX;
/* NOTREACHED */
}
RC_UNUSED static char *xstrdup(const char *str)
{
char *value;
if (!str)
return (NULL);
value = strdup(str);
if (value)
return (value);
ERRX;
/* NOTREACHED */
}
RC_UNUSED static FILE *xopen_memstream(char **ptr, size_t *sizeloc)
{
FILE *f = open_memstream(ptr, sizeloc);
if (f)
return f;
ERRX;
}
RC_UNUSED static void xclose_memstream(FILE *f)
{
fflush(f);
if (ferror(f) || fclose(f) != 0)
ERRX;
}
#undef ERRX
/*
* basename_c never modifies the argument. As such, if there is a trailing
* slash then an empty string is returned.
*/
RC_UNUSED static const char *basename_c(const char *path)
{
const char *slash = strrchr(path, '/');
if (slash)
return (++slash);
return (path);
}
RC_UNUSED static FILE *do_fopenat(int dirfd, const char *pathname, int mode)
{
int fd = openat(dirfd, pathname, mode, 0666);
const char *fmode;
FILE *fp;
if (fd == -1)
return NULL;
/* O_CREAT and O_TRUNC in modes 'a', 'w+', 'a+' don't
* really matter after the file has been opened.
*
* Some implementations have O_RDONLY defined to zero,
* thus making it impossible to detect, so, we default
* to "r" if no other mask fully matches. */
if ((mode & O_RDWR) == O_RDWR)
fmode = "r+";
else if ((mode & O_WRONLY) == O_WRONLY)
fmode = "w";
else
fmode = "r";
if (!(fp = fdopen(fd, fmode)))
close(fd);
return fp;
}
RC_UNUSED static DIR *do_opendirat(int dirfd, const char *pathname)
{
int fd = openat(dirfd, pathname, O_RDONLY | O_DIRECTORY);
DIR *dp;
if (fd == -1)
return NULL;
if (!(dp = fdopendir(fd)))
close(fd);
return dp;
}
RC_UNUSED static DIR *do_dopendir(int dirfd)
{
int fd = dup(dirfd);
DIR *dp;
if (fd == -1)
return NULL;
if (!(dp = fdopendir(fd)))
close(fd);
return dp;
}
/*
* This is an OpenRC specific version of the asprintf() function.
* We do this to avoid defining the _GNU_SOURCE feature test macro on
* glibc systems and to ensure that we have a consistent function across
* platforms. This also allows us to call our xmalloc and xrealloc
* functions to handle memory allocation.
* this function was originally written by Mike Frysinger.
*/
RC_UNUSED RC_PRINTF(2,3) static int xasprintf(char **strp, const char *fmt, ...)
{
va_list ap;
int len;
int memlen;
char *ret;
/*
* Start with a buffer size that should cover the vast majority of uses
* (path construction).
*/
memlen = 4096;
ret = xmalloc(memlen);
va_start(ap, fmt);
len = vsnprintf(ret, memlen, fmt, ap);
va_end(ap);
if (len >= memlen) {
/*
* Output was truncated, so increase buffer to exactly what we need.
*/
memlen = len + 1;
ret = xrealloc(ret, memlen);
va_start(ap, fmt);
len = vsnprintf(ret, len + 1, fmt, ap);
va_end(ap);
}
if (len < 0 || len >= memlen) {
/* Give up! */
fprintf(stderr, "xasprintf: unable to format a buffer\n");
free(ret);
exit(1);
}
*strp = ret;
return len;
}
RC_UNUSED static ssize_t xgetline(char **restrict lineptr, size_t *restrict n, FILE *restrict stream)
{
ssize_t ret = getline(lineptr, n, stream);
if (ret <= 0)
return ret;
if ((*lineptr)[ret - 1] == '\n')
(*lineptr)[--ret] = '\0';
return ret;
}
#endif
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