Files
xen/tools/xenstore/utils.c
T

128 lines
2.1 KiB
C

#define _GNU_SOURCE
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <signal.h>
#include "utils.h"
void xprintf(const char *fmt, ...)
{
static FILE *out = NULL;
va_list args;
if (!out)
out = stderr;
va_start(args, fmt);
vfprintf(out, fmt, args);
va_end(args);
fflush(out);
}
void barf(const char *fmt, ...)
{
char *str;
va_list arglist;
xprintf("FATAL: ");
va_start(arglist, fmt);
vasprintf(&str, fmt, arglist);
va_end(arglist);
xprintf("%s\n", str);
free(str);
exit(1);
}
void barf_perror(const char *fmt, ...)
{
char *str;
int err = errno;
va_list arglist;
xprintf("FATAL: ");
va_start(arglist, fmt);
vasprintf(&str, fmt, arglist);
va_end(arglist);
xprintf("%s: %s\n", str, strerror(err));
free(str);
exit(1);
}
void *_realloc_array(void *ptr, size_t size, size_t num)
{
if (num >= SIZE_MAX/size)
return NULL;
return realloc_nofail(ptr, size * num);
}
void *realloc_nofail(void *ptr, size_t size)
{
ptr = realloc(ptr, size);
if (ptr)
return ptr;
barf("realloc of %zu failed", size);
}
void *malloc_nofail(size_t size)
{
void *ptr = malloc(size);
if (ptr)
return ptr;
barf("malloc of %zu failed", size);
}
/* This version adds one byte (for nul term) */
void *grab_file(const char *filename, unsigned long *size)
{
unsigned int max = 16384;
int ret, fd;
void *buffer;
if (streq(filename, "-"))
fd = dup(STDIN_FILENO);
else
fd = open(filename, O_RDONLY, 0);
if (fd == -1)
return NULL;
buffer = malloc(max+1);
if (!buffer)
goto error;
*size = 0;
while ((ret = read(fd, buffer + *size, max - *size)) > 0) {
*size += ret;
if (*size == max) {
void *nbuffer;
max *= 2;
nbuffer = realloc(buffer, max + 1);
if (!nbuffer)
goto error;
buffer = nbuffer;
}
}
if (ret < 0)
goto error;
((char *)buffer)[*size] = '\0';
close(fd);
return buffer;
error:
free(buffer);
close(fd);
return NULL;
}
void release_file(void *data, unsigned long size __attribute__((unused)))
{
free(data);
}