83 lines
2.5 KiB
C++
83 lines
2.5 KiB
C++
/*
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* s3fs - FUSE-based file system backed by Amazon S3
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*
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* Copyright(C) 2021 Andrew Gaul <andrew@gaul.org>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#include <cstdio>
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#include <cstdlib>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <unistd.h>
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// [NOTE]
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// This is a program used for file size inspection.
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// File size checking should be done by the caller of this program.
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// This program truncates the file and reads the file in another process
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// between truncate and flush(close file).
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//
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int main(int argc, char *argv[])
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{
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if(argc != 3){
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fprintf(stderr, "[ERROR] Wrong paraemters\n");
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fprintf(stdout, "[Usage] truncate_read_file <file path> <truncate size(bytes)>\n");
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exit(EXIT_FAILURE);
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}
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const char* filepath = argv[1];
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off_t size = static_cast<off_t>(strtoull(argv[2], nullptr, 10));
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int fd;
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// open file
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if(-1 == (fd = open(filepath, O_RDWR))){
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fprintf(stderr, "[ERROR] Could not open file(%s)\n", filepath);
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exit(EXIT_FAILURE);
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}
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// truncate
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if(0 != ftruncate(fd, size)){
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fprintf(stderr, "[ERROR] Could not truncate file(%s) to %lld byte.\n", filepath, (long long)size);
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close(fd);
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exit(EXIT_FAILURE);
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}
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// run sub-process for reading file(cat)
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char szCommand[1024];
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snprintf(szCommand, sizeof(szCommand), "cat %s >/dev/null 2>&1", filepath);
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szCommand[sizeof(szCommand) - 1] = '\0'; // for safety
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if(0 != system(szCommand)){
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fprintf(stderr, "[ERROR] Failed to run sub-process(cat).\n");
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close(fd);
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exit(EXIT_FAILURE);
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}
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// close file(flush)
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close(fd);
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exit(EXIT_SUCCESS);
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}
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/*
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* Local variables:
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* tab-width: 4
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* c-basic-offset: 4
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* End:
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* vim600: expandtab sw=4 ts=4 fdm=marker
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* vim<600: expandtab sw=4 ts=4
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*/
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