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/*
* Copyright (c) 2022 Egor Tensin <Egor.Tensin@gmail.com>
* This file is part of the "cimple" project.
* For details, see https://github.com/egor-tensin/cimple.
* Distributed under the MIT License.
*/
#include "process.h"
#include "file.h"
#include "log.h"
#include <fcntl.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <unistd.h>
static int exec_child(const char *args[], const char *envp[])
{
static const char *default_envp[] = {NULL};
if (!envp)
envp = default_envp;
int ret = execvpe(args[0], (char *const *)args, (char *const *)envp);
if (ret < 0) {
log_errno("execvpe");
return ret;
}
return ret;
}
static int wait_for_child(pid_t pid, int *ec)
{
int status;
pid_t ret = waitpid(pid, &status, __WNOTHREAD);
if (ret < 0) {
log_errno("waitpid");
return ret;
}
if (WIFEXITED(status))
*ec = WEXITSTATUS(status);
else
*ec = -1;
return 0;
}
int proc_spawn(const char *args[], const char *envp[], int *ec)
{
pid_t child_pid = fork();
if (child_pid < 0) {
log_errno("fork");
return child_pid;
}
if (!child_pid)
exit(exec_child(args, envp));
return wait_for_child(child_pid, ec);
}
static int redirect_and_exec_child(int pipe_fds[2], const char *args[], const char *envp[])
{
int ret = 0;
file_close(pipe_fds[0]);
ret = dup2(pipe_fds[1], STDOUT_FILENO);
if (ret < 0) {
log_errno("dup2");
return ret;
}
ret = dup2(pipe_fds[1], STDERR_FILENO);
if (ret < 0) {
log_errno("dup2");
return ret;
}
return exec_child(args, envp);
}
int proc_capture(const char *args[], const char *envp[], struct proc_output *result)
{
static const int flags = O_CLOEXEC;
int pipe_fds[2];
int ret = 0;
ret = pipe2(pipe_fds, flags);
if (ret < 0) {
log_errno("pipe2");
return -1;
}
pid_t child_pid = fork();
if (child_pid < 0) {
log_errno("fork");
goto close_pipe;
}
if (!child_pid)
exit(redirect_and_exec_child(pipe_fds, args, envp));
file_close(pipe_fds[1]);
ret = file_read(pipe_fds[0], &result->data, &result->data_size);
if (ret < 0)
goto close_pipe;
ret = wait_for_child(child_pid, &result->ec);
if (ret < 0)
goto free_data;
goto close_pipe;
free_data:
free(result->data);
close_pipe:
file_close(pipe_fds[0]);
/* No errno checking here, we might've already closed the write end. */
close(pipe_fds[1]);
return ret;
}
int proc_output_create(struct proc_output **_output)
{
struct proc_output *output = calloc(1, sizeof(struct proc_output));
if (!output) {
log_errno("calloc");
return -1;
}
output->ec = 0;
output->data = NULL;
output->data_size = 0;
*_output = output;
return 0;
}
void proc_output_destroy(struct proc_output *output)
{
free(output->data);
free(output);
}
void proc_output_dump(const struct proc_output *output)
{
log("Process exit code: %d\n", output->ec);
log("Process output: %zu bytes\n", output->data_size);
}
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