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#include "program.h"
#include "buffer.h"
#include <unistd.h>
#include <sys/wait.h>
#include <sys/prctl.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#define READ_END 0
#define WRITE_END 1
int program_buffer_write_callback(char *data, int size, void *userdata) {
Buffer *buffer = userdata;
buffer_append(buffer, data, size);
return 0;
}
static int program_read_output(int process_id, int read_fd, ProgramOutputCallback output_callback, void *userdata) {
int status;
char buffer[4097];
for(;;) {
ssize_t bytes_read = read(read_fd, buffer, sizeof(buffer) - 1);
if(bytes_read == 0) {
break;
} else if(bytes_read == -1) {
int err = errno;
fprintf(stderr, "Failed to read from pipe, error: %s\n", strerror(err));
return -err;
}
buffer[bytes_read] = '\0';
if(output_callback && output_callback(buffer, bytes_read, userdata) != 0)
break;
}
if(waitpid(process_id, &status, 0) == -1) {
perror("waitpid failed");
return -5;
}
if(!WIFEXITED(status))
return -4;
int exit_status = WEXITSTATUS(status);
if(exit_status != 0)
return -exit_status;
return 0;
}
int program_exec(const char **args, ProgramOutputCallback output_callback, void *userdata) {
/* 1 argument */
if(args[0] == NULL)
return -1;
int fd[2];
if(pipe(fd) == -1) {
perror("Failed to open pipe");
return -2;
}
pid_t parent_pid = getpid();
pid_t pid = fork();
if(pid == -1) {
perror("Failed to fork");
close(fd[READ_END]);
close(fd[WRITE_END]);
return -3;
} else if(pid == 0) { /* child */
if(prctl(PR_SET_PDEATHSIG, SIGTERM) == -1) {
perror("prctl(PR_SET_PDEATHSIG, SIGTERM) failed");
exit(127);
}
/* Test if the parent died before the above call to prctl */
if(getppid() != parent_pid)
exit(127);
dup2(fd[WRITE_END], STDOUT_FILENO);
close(fd[READ_END]);
close(fd[WRITE_END]);
execvp(args[0], (char* const*)args);
perror("execvp");
exit(127);
} else { /* parent */
close(fd[WRITE_END]);
int result = program_read_output(pid, fd[READ_END], output_callback, userdata);
if(result != 0) {
fprintf(stderr, "Failed to execute program (");
const char **arg = args;
while(*arg) {
if(arg != args)
fputc(' ', stderr);
fprintf(stderr, "'%s'", *arg);
++arg;
}
fprintf(stderr, ")\n");
}
close(fd[READ_END]);
return result;
}
}
int program_exec_async(const char **args, int *process_id, int *stdin_file, int *stdout_file) {
int result = 0;
/* 1 argument */
if(args[0] == NULL)
return -1;
int stdin_fd[2] = { -1, -1 };
int stdout_fd[2] = { -1, -1 };
if(stdin_file) {
if(pipe(stdin_fd) == -1) {
perror("Failed to open pipe");
result = -2;
goto cleanup;
}
}
if(stdout_file) {
if(pipe(stdout_fd) == -1) {
perror("Failed to open pipe");
result = -2;
goto cleanup;
}
}
pid_t parent_pid = getpid();
pid_t pid = fork();
if(pid == -1) {
result = -errno;
perror("failed to fork");
goto cleanup;
} else if(pid == 0) { /* child */
if(prctl(PR_SET_PDEATHSIG, SIGTERM) == -1) {
perror("prctl(PR_SET_PDEATHSIG, SIGTERM) failed");
exit(127);
}
/* Test if the parent died before the above call to prctl */
if(getppid() != parent_pid)
exit(127);
if(stdin_file) {
dup2(stdin_fd[READ_END], STDIN_FILENO);
close(stdin_fd[READ_END]);
close(stdin_fd[WRITE_END]);
}
if(stdout_file) {
dup2(stdout_fd[WRITE_END], STDOUT_FILENO);
close(stdout_fd[READ_END]);
close(stdout_fd[WRITE_END]);
}
execvp(args[0], (char* const*)args);
perror("execvp");
exit(127);
} else { /* parent */
if(process_id)
*process_id = pid;
if(stdin_file)
close(stdin_fd[READ_END]);
if(stdout_file)
close(stdout_fd[WRITE_END]);
*stdin_file = stdin_fd[WRITE_END];
*stdout_file = stdout_fd[READ_END];
return 0;
}
cleanup:
if(stdin_fd[0] != -1) close(stdin_fd[0]);
if(stdin_fd[1] != -1) close(stdin_fd[1]);
if(stdout_fd[0] != -1) close(stdout_fd[0]);
if(stdout_fd[1] != -1) close(stdout_fd[1]);
return result;
}
int program_wait_until_exit(int process_id, int stdin_file, int stdout_file, ProgramOutputCallback output_callback, void *userdata) {
if(stdin_file != -1)
close(stdin_file);
int result = program_read_output(process_id, stdout_file, output_callback, userdata);
if(stdout_file != -1)
close(stdout_file);
return result;
}
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