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// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#include "process.h"
#include "pipe.h"
#include "close_all_files.h"
#include <vespa/vespalib/util/size_literals.h>
#include <vespa/vespalib/util/require.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <csignal>
#include <unistd.h>
#include <fcntl.h>
namespace vespalib {
Process::Process(const vespalib::string &cmd, bool capture_stderr)
: _pid(-1),
_in(),
_out(),
_in_buf(4_Ki),
_out_buf(4_Ki),
_eof(false)
{
Pipe pipe_in = Pipe::create();
Pipe pipe_out = Pipe::create();
REQUIRE(pipe_in.valid() && pipe_out.valid());
pid_t pid = fork();
REQUIRE(pid != -1);
if (pid == 0) {
dup2(pipe_in.read_end.fd(), STDIN_FILENO);
dup2(pipe_out.write_end.fd(), STDOUT_FILENO);
if (capture_stderr) {
dup2(pipe_out.write_end.fd(), STDERR_FILENO);
} else {
int dev_null = open("/dev/null", O_WRONLY);
dup2(dev_null, STDERR_FILENO);
::close(dev_null);
}
close_all_files();
const char *sh_args[4];
sh_args[0] = "sh";
sh_args[1] = "-c";
sh_args[2] = cmd.c_str();
sh_args[3] = nullptr;
execv("/bin/sh", const_cast<char * const *>(sh_args));
abort();
} else {
_pid = pid;
pipe_in.read_end.reset();
pipe_out.write_end.reset();
_in.reset(pipe_in.write_end.release());
_out.reset(pipe_out.read_end.release());
}
}
Memory
Process::obtain()
{
if ((_out_buf.obtain().size == 0) && !_eof) {
WritableMemory buf = _out_buf.reserve(4_Ki);
ssize_t res = read(_out.fd(), buf.data, buf.size);
while ((res == -1) && (errno == EINTR)) {
res = read(_out.fd(), buf.data, buf.size);
}
REQUIRE(res >= 0);
if (res > 0) {
_out_buf.commit(res);
} else {
_eof = true;
}
}
return _out_buf.obtain();
}
Input &
Process::evict(size_t bytes)
{
_out_buf.evict(bytes);
return *this;
}
WritableMemory
Process::reserve(size_t bytes)
{
return _in_buf.reserve(bytes);
}
Output &
Process::commit(size_t bytes)
{
_in_buf.commit(bytes);
Memory buf = _in_buf.obtain();
while (buf.size > 0) {
ssize_t res = write(_in.fd(), buf.data, buf.size);
while ((res == -1) && (errno == EINTR)) {
res = write(_in.fd(), buf.data, buf.size);
}
REQUIRE(res > 0);
_in_buf.evict(res);
buf = _in_buf.obtain();
}
return *this;
}
vespalib::string
Process::read_line() {
vespalib::string line;
for (auto mem = obtain(); (mem.size > 0); mem = obtain()) {
for (size_t i = 0; i < mem.size; ++i) {
if (mem.data[i] == '\n') {
evict(i + 1);
return line;
} else {
line.push_back(mem.data[i]);
}
}
evict(mem.size);
}
return line;
}
int
Process::join()
{
pid_t res;
int status;
do {
res = waitpid(_pid, &status, 0);
} while ((res == -1) && (errno == EINTR));
REQUIRE_EQ(res, _pid);
_pid = -1; // make invalid
if (WIFEXITED(status)) {
return WEXITSTATUS(status);
}
return (0x80000000 | status);
}
Process::~Process()
{
if (valid()) {
kill(_pid, SIGKILL);
join();
}
}
bool
Process::run(const vespalib::string &cmd, vespalib::string &output)
{
Process proc(cmd);
proc.close();
for (auto mem = proc.obtain(); mem.size > 0; mem = proc.obtain()) {
output.append(mem.data, mem.size);
proc.evict(mem.size);
}
if (!output.empty() && (output.find('\n') == (output.size() - 1))) {
output.pop_back();
}
return (proc.join() == 0);
}
bool
Process::run(const vespalib::string &cmd)
{
vespalib::string ignore_output;
return run(cmd, ignore_output);
}
} // namespace vespalib
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