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#include <stdio.h>
#include <unistd.h>
#include <dirent.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <AK/AKString.h>
#include <AK/StringBuilder.h>
#include <AK/Vector.h>
#include <LibCore/CArgsParser.h>
#include <LibCore/CDirIterator.h>
static String read_var(const String& name)
{
StringBuilder builder;
builder.append("/proc/sys/");
builder.append(name);
auto path = builder.to_string();
int fd = open(path.characters(), O_RDONLY);
if (fd < 0) {
perror("open");
exit(1);
}
char buffer[1024];
int nread = read(fd, buffer, sizeof(buffer));
close(fd);
if (nread < 0) {
perror("read");
exit(1);
}
return String(buffer, nread, Chomp);
}
static void write_var(const String& name, const String& value)
{
StringBuilder builder;
builder.append("/proc/sys/");
builder.append(name);
auto path = builder.to_string();
int fd = open(path.characters(), O_WRONLY);
if (fd < 0) {
perror("open");
exit(1);
}
int nwritten = write(fd, value.characters(), value.length());
if (nwritten < 0) {
perror("read");
exit(1);
}
close(fd);
}
static int handle_show_all()
{
CDirIterator di("/proc/sys", CDirIterator::SkipDots);
if (di.has_error()) {
fprintf(stderr, "CDirIterator: %s\n", di.error_string());
return 1;
}
char pathbuf[PATH_MAX];
while (di.has_next()) {
String name = di.next_path();
sprintf(pathbuf, "/proc/sys/%s", name.characters());
int fd = open(pathbuf, O_RDONLY);
if (fd < 0) {
perror("open");
continue;
}
char buffer[1024];
int nread = read(fd, buffer, sizeof(buffer));
close(fd);
if (nread < 0) {
perror("read");
continue;
}
buffer[nread] = '\0';
printf("%s = %s", name.characters(), buffer);
if (nread && buffer[nread - 1] != '\n')
printf("\n");
}
return 0;
}
static int handle_var(const String& var)
{
String spec(var.characters(), Chomp);
auto parts = spec.split('=');
String variable_name = parts[0];
bool is_write = parts.size() > 1;
if (!is_write) {
printf("%s = %s\n", variable_name.characters(), read_var(variable_name).characters());
return 0;
}
printf("%s = %s", variable_name.characters(), read_var(variable_name).characters());
write_var(variable_name, parts[1]);
printf(" -> %s\n", read_var(variable_name).characters());
return 0;
}
int main(int argc, char** argv)
{
CArgsParser args_parser("sysctl");
args_parser.add_arg("a", "show all variables");
args_parser.add_single_value("variable=[value]");
CArgsParserResult args = args_parser.parse(argc, (const char**)argv);
if (args.is_present("a")) {
return handle_show_all();
} else if (args.get_single_values().size() != 1) {
args_parser.print_usage();
return 0;
}
Vector<String> values = args.get_single_values();
return handle_var(values[0]);
}
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