mirror of https://github.com/leahneukirchen/mblaze
You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
125 lines
2.2 KiB
C
125 lines
2.2 KiB
C
#include <poll.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/wait.h>
|
|
#include <unistd.h>
|
|
|
|
int
|
|
filter(char *input, size_t inlen, char *cmd, char **outputo, size_t *outleno)
|
|
{
|
|
char *output;
|
|
ssize_t outlen;
|
|
ssize_t outalloc = 4096;
|
|
pid_t pid;
|
|
|
|
output = malloc(outalloc);
|
|
outlen = 0;
|
|
|
|
int pipe0[2];
|
|
int pipe1[2];
|
|
|
|
if (pipe(pipe0) != 0 || pipe(pipe1) != 0)
|
|
goto fail;
|
|
|
|
char *argv[] = { "/bin/sh", "-c", cmd, (char *)0 };
|
|
|
|
if (!(pid = fork())) {
|
|
dup2(pipe0[0], 0);
|
|
close(pipe0[1]);
|
|
close(pipe0[0]);
|
|
|
|
dup2(pipe1[1], 1);
|
|
close(pipe1[0]);
|
|
close(pipe1[1]);
|
|
|
|
execvp(argv[0], argv);
|
|
exit(-1);
|
|
}
|
|
close(pipe0[0]);
|
|
close(pipe1[1]);
|
|
|
|
if (pid < 0) {
|
|
close(pipe0[1]);
|
|
close(pipe1[0]);
|
|
goto fail;
|
|
}
|
|
|
|
struct pollfd fds[2];
|
|
|
|
fds[0].fd = pipe1[0];
|
|
fds[0].events = POLLIN;
|
|
fds[1].fd = pipe0[1];
|
|
fds[1].events = POLLOUT;
|
|
|
|
while ((fds[0].fd >= 0 || fds[1].fd >= 0) &&
|
|
poll(fds, sizeof fds / sizeof fds[0], -1) >= 0) {
|
|
if (fds[0].revents & POLLIN) {
|
|
if (outlen + 512 > outalloc) {
|
|
outalloc *= 2;
|
|
if (outalloc < 0)
|
|
exit(-1);
|
|
output = realloc(output, outalloc);
|
|
if (!output)
|
|
exit(-1);
|
|
}
|
|
ssize_t ret = read(fds[0].fd, output + outlen, 512);
|
|
if (ret > 0)
|
|
outlen += ret;
|
|
else if (ret < 0)
|
|
close(fds[0].fd);
|
|
} else if (fds[0].revents & (POLLERR | POLLHUP | POLLNVAL)) {
|
|
fds[0].fd = -1;
|
|
}
|
|
|
|
if (fds[1].revents & POLLOUT) {
|
|
ssize_t ret = write(fds[1].fd, input, inlen);
|
|
if (ret > 0) {
|
|
input += ret;
|
|
inlen -= ret;
|
|
}
|
|
if (ret <= 0 || inlen == 0)
|
|
close(fds[1].fd);
|
|
} else if (fds[1].revents & (POLLERR | POLLHUP | POLLNVAL)) {
|
|
fds[1].fd = -1;
|
|
}
|
|
}
|
|
|
|
// ok to fail when closed already
|
|
close(pipe0[1]);
|
|
close(pipe1[0]);
|
|
|
|
int status;
|
|
waitpid(pid, &status, 0);
|
|
|
|
*outputo = output;
|
|
*outleno = outlen;
|
|
|
|
return WEXITSTATUS(status);
|
|
|
|
fail:
|
|
*outputo = 0;
|
|
*outleno = 0;
|
|
|
|
return -1;
|
|
}
|
|
|
|
#ifdef TEST
|
|
int
|
|
main()
|
|
{
|
|
char *input = "foo\nbar\nbaz";
|
|
int e;
|
|
|
|
char *output;
|
|
size_t outlen;
|
|
|
|
e = filter(input, strlen(input), "rev;exit 2", &output, &outlen);
|
|
|
|
fwrite(output, 1, outlen, stdout);
|
|
printf("%ld -> %d\n", outlen, e);
|
|
|
|
return 0;
|
|
}
|
|
#endif
|