Your top 10 commands - Printable Version

Code:
#include <stdio.h>

#include <errno.h>

#include <stdlib.h>

#include <unistd.h>

#include <string.h>

#include <stdbool.h>

#include <sys/socket.h>

#include <sys/un.h>



#define LINE_SIZE 1024



int recv_first_line(int fd, char *line_buf, size_t line_sz)

{

    char *buf = line_buf;

    size_t sz = line_sz;



    for (ssize_t n; sz > 0 && (n = recv(fd, buf, sz, MSG_WAITALL)) != 0; sz -= n, buf += n) {

        if (n < 0) {

            return -errno;

        }

    }

    line_buf[line_sz - 1] = '\0';

    line_buf[strcspn(line_buf, "\r\n")] = '\0';

    return 0;

}



int handle_connection(int fd, char **argv, char **placeholder)

{

    char line[LINE_SIZE] = {0};

    int err;



    err = shutdown(fd, SHUT_WR);

    if (err) {

        perror("shutdown");

        return -errno;

    }



    err = recv_first_line(fd, line, sizeof(line));

    if (err) {

        perror("recv_first_line");

        return err;

    }



    *placeholder = line;



    printf("unixargs:");

    for (size_t i = 0; argv[i] != NULL; i++) {

        printf(" %s", argv[i]);

    }

    printf("\n");



    switch (fork()) {

    case -1:

        perror("fork");

        return -errno;

    case 0:

        execvp(argv[0], argv);

        perror(argv[0]);

        return -errno;

    }



    return 0;

}



int xserver(char *path, char **argv, char **placeholder)

{

    struct sockaddr_un sun = { .sun_family = AF_UNIX };

    int sockfd, netfd, err;



    sockfd = socket(AF_UNIX, SOCK_STREAM, 0);

    if (sockfd < 0) {

        perror("socket(AF_UNIX)");

        return -errno;

    }



    strncpy(sun.sun_path, path, sizeof(sun.sun_path) - 1);

    err = bind(sockfd, (struct sockaddr *)&sun, sizeof(sun));

    if (err) {

        perror(path);

        return -errno;

    }



    err = listen(sockfd, 10);

    if (err) {

        perror(path);

        return -errno;

    }



    while (true) {

        netfd = accept(sockfd, NULL, NULL);

        if (netfd < 0) {

            perror(path);

            continue;

        }



        handle_connection(netfd, argv, placeholder);

    }



    return 0;

}



void usage(char *argv0)

{

    fprintf(stderr, "Usage: %s ./path.sock cmd [args...] {} [args...]\n", argv0);

    exit(1);

}



int main(int argc, char **argv)

{

    char **placeholder = NULL;

    int err;



    if (argc < 4) {

        usage(argv[0]);

    }



    for (int i = 3; i < argc; i++) {

        if (strcmp(argv[i], "{}") == 0) {

            placeholder = &argv[i];

            break;

        }

    }

    if (placeholder == NULL) {

        usage(argv[0]);

    }



    err = xserver(argv[1], argv + 2, placeholder);

    if (err) {

        fprintf(stderr, "failed to run xserver, exiting\n");

        return -err;

    }



    return 0;

}