ladybird/Userland/truncate.cpp
2020-02-06 15:04:03 +01:00

133 lines
3.6 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <LibCore/ArgsParser.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;
int 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;
}
bool ok;
size = str.to_int(ok);
if (!ok) {
args_parser.print_usage(stderr, argv[0]);
return 1;
}
}
if (reference) {
struct stat st;
int rc = stat(reference, &st);
if (rc < 0) {
perror("stat");
return 1;
}
op = OP_Set;
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;
}