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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibCore/ArgsParser.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/stat.h>
#include <unistd.h>
enum TruncateOperation {
OP_Set,
OP_Grow,
OP_Shrink,
};
int main(int argc, char** argv)
{
const char* resize = nullptr;
const char* reference = nullptr;
const char* file = nullptr;
Core::ArgsParser args_parser;
args_parser.add_option(resize, "Resize the target file to (or by) this size. Prefix with + or - to expand or shrink the file, or a bare number to set the size exactly", "size", 's', "size");
args_parser.add_option(reference, "Resize the target file to match the size of this one", "reference", 'r', "file");
args_parser.add_positional_argument(file, "File path", "file");
args_parser.parse(argc, argv);
if (!resize && !reference) {
args_parser.print_usage(stderr, argv[0]);
return 1;
}
if (resize && reference) {
args_parser.print_usage(stderr, argv[0]);
return 1;
}
auto op = OP_Set;
off_t size = 0;
if (resize) {
String str = resize;
switch (str[0]) {
case '+':
op = OP_Grow;
str = str.substring(1, str.length() - 1);
break;
case '-':
op = OP_Shrink;
str = str.substring(1, str.length() - 1);
break;
}
auto size_opt = str.to_int<off_t>();
if (!size_opt.has_value()) {
args_parser.print_usage(stderr, argv[0]);
return 1;
}
size = size_opt.value();
}
if (reference) {
struct stat st;
int rc = stat(reference, &st);
if (rc < 0) {
perror("stat");
return 1;
}
size = st.st_size;
}
int fd = open(file, O_RDWR | O_CREAT, 0666);
if (fd < 0) {
perror("open");
return 1;
}
struct stat st;
if (fstat(fd, &st) < 0) {
perror("fstat");
return 1;
}
switch (op) {
case OP_Set:
break;
case OP_Grow:
size = st.st_size + size;
break;
case OP_Shrink:
size = st.st_size - size;
break;
}
if (ftruncate(fd, size) < 0) {
perror("ftruncate");
return 1;
}
if (close(fd) < 0) {
perror("close");
return 1;
}
return 0;
}
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