utils-std

sync.c (1923B)

// utils-std: Collection of commonly available Unix tools
// SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
// SPDX-License-Identifier: MPL-2.0
#define _POSIX_C_SOURCE 200809L
#define _GNU_SOURCE       // syncfs
#define _XOPEN_SOURCE 700 // sync
#include <errno.h>
#include <fcntl.h> // open, O_*
#include <stdbool.h>
#include <stdio.h>  // fprintf
#include <stdlib.h> // abort
#include <string.h> // strerror
#include <unistd.h> // fsync, sync, getopt, syncfs
int
main(int argc, char *argv[])
{
	int err = 0;
	int (*sync_func)(int) = fsync;
	int c = -1;
	while((c = getopt(argc, argv, ":df")) != -1)
	{
		switch(c)
		{
		case 'd':
			sync_func = fdatasync;
			break;
		case 'f':
#ifdef HAS_SYNCFS
			sync_func = syncfs;
			break;
#else
			fprintf(stderr,
			        "sync: error: System doesn't supports syncfs(3), continuing with error status set\n");
			err = 1;
			break;
#endif
		case '?':
			fprintf(stderr,
			        "sync: error: Unrecognized option '-%c', continuing with error status set\n",
			        optopt);
			err = 1;
			break;
		default:
			abort();
		}
	}
	argc -= optind;
	argv += optind;
	if(argc == 0)
	{
#ifdef HAS_SYNCFS
		if(sync_func == syncfs) fprintf(stderr, "sync: warning: Option -f passed without arguments\n");
#endif
		sync();
		return err;
	}
	for(int i = 0; i < argc; i++)
	{
		int fd = open(argv[i], O_RDONLY);
		if(fd < 0)
		{
			fprintf(stderr, "sync: error: Failed opening file '%s': %s\n", argv[i], strerror(errno));
			return 1;
		}
		if(sync_func(fd) < 0)
		{
			fprintf(stderr,
			        "sync: error: Failed synchronizing changes related to file '%s': %s\n",
			        argv[i],
			        strerror(errno));
			return 1;
		}
		if(close(fd) < 0)
		{
			fprintf(stderr,
			        "sync: error: Failed closing file-descriptor of file '%s': %s\n",
			        argv[i],
			        strerror(errno));
			return 1;
		}
	}
	return err;
}