diff options
Diffstat (limited to 'chat.c')
| -rw-r--r-- | chat.c | 220 |
1 files changed, 220 insertions, 0 deletions
@@ -0,0 +1,220 @@ +// clang -no-pie -static chat.c -lpthread -ochat -Wl,-z,now -Wl,-z,relro +// strip -g chat + +#include <poll.h> +#include <pthread.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + + +#define MAXCHANNELS 5 + +static int cpipe[2]; + +static pthread_t channels[MAXCHANNELS]; +static int active[MAXCHANNELS] = {0}; +static int pipes[MAXCHANNELS][2]; + +static bool quit = false; + +#define QUIT_CHANNEL(x) do { \ + active[x] = 2; \ + return NULL; \ + } while (0); + +static char command[32] = {0}; + + +static int wait_loop(bool is_command_channel, int channel) { + struct pollfd pfd; + if (is_command_channel) { + pfd.fd = cpipe[0]; + } else { + pfd.fd = pipes[channel][0]; + } + pfd.events = POLLIN; + + if (is_command_channel && channel != -1) { + write(pipes[channel][1], "c", 1); + } else if (!is_command_channel) { + write(cpipe[1], "c", 1); + } + + while (1) { + int ret; + if ((ret = poll(&pfd, 1, 1000)) == -1) { + // error + return 1; + } else if (ret == 0) { + // timeout + if (quit == true) { + return 1; + } + continue; + } + + char c; + if (is_command_channel) { + read(cpipe[0], &c, 1); + } else { + read(pipes[channel][0], &c, 1); + } + break; + } + + return 0; +} + +static void chat_channel_help() { + printf("Chat Commands:\n" + "\t/e\t- Echo - The first line following this command specifies the number of characters to echo.\n" + "\t/pc\t- Pause Chat Channel - Return to Command Channel. The Chat Channel stays open.\n" + "\t/qc\t- Quit Chat Channel - Return to Command Channel. The Chat Channel is terminated.\n" + "\t/h\t- Help - Print this help message.\n" + "That's all for now :/\n"); +} + +static void *chat_channel_handler(void * arg) { + int channel = (int) arg; + + if (pipe(pipes[channel]) == -1) { + printf("Chat Channel Creation Failed: Pipes\n"); + QUIT_CHANNEL(channel); + } + + printf("Chat Channel %d:\n", channel+1); + + while (1) { + printf("> "); + + if(!fgets(command, 32, stdin)) { + QUIT_CHANNEL(channel); + } + + if (strlen(command) == 3 && command[0] == '/' && command[1] == 'e') { + if(!fgets(command, 32, stdin)) { + printf("Chat Command Error: Reading Echo Size\n"); + } + + int length = atoi(command) + 1; + char *line = (char *)alloca(length); + + if (!fgets(line, length, stdin)) { + QUIT_CHANNEL(channel); + } + + write(1, line, strlen(line)); + write(1, "\n", 1); + } else if (strlen(command) == 4 && command[0] == '/' && command[1] == 'p' && command[2] == 'c') { + if (wait_loop(false, channel)) { + QUIT_CHANNEL(channel); + } + + printf("Chat Channel %d:\n", channel+1); + } else if (strlen(command) == 4 && command[0] == '/' && command[1] == 'q' && command[2] == 'c') { + write(cpipe[1], "c", 1); + QUIT_CHANNEL(channel); + } else if (strlen(command) == 3 && command[0] == '/' && command[1] == 'h') { + chat_channel_help(); + } + } +} + +static void command_channel_help() { + printf("Command Commands:\n" + "\t/nc\t- New Chat Channel - Create and join a new Chat Channel.\n" + "\t/jc x\t- Join Chat Channel - Join the Chat Channel number x.\n" + "\t/lc\t- List Chat Channels - Lists the Chat Channels.\n" + "\t/q\t- Quit - Quit this awesome chat program.\n" + "\t/h\t- Help - Print this help message.\n"); +} + +int main() { + if (pipe(cpipe) == -1) { + return 1; + } + + printf("Command Channel:\n"); + + while (1) { + printf("> "); + + if(!fgets(command, 32, stdin)) { + return 1; + } + + if (strlen(command) == 4 && command[0] == '/' && command[1] == 'n' && command[2] == 'c') { + int channel = -1; + for (int i = 0; i < MAXCHANNELS; i++) { + if (active[i] == 0) { + channel = i; + break; + } + } + + if (channel == -1) { + printf("Chat Channel Creation Failed: No channel slots left\n"); + } else { + pthread_attr_t attr; + pthread_attr_init(&attr); + pthread_attr_setstacksize(&attr, 0x3C000); + + pthread_create(&channels[channel], &attr, chat_channel_handler, (void *)channel); + active[channel] = 1; + + wait_loop(true, -1); + printf("Command Channel:\n"); + } + } else if (command[0] == '/' && command[1] == 'j' && command[2] == 'c' && command[3] == ' ') { + printf("Joining Chat Channel.\n"); + + int channel = atoi(command + 4) - 1; + + if (0 <= channel && channel < MAXCHANNELS && active[channel] == 1) { + wait_loop(true, channel); + printf("Command Channel:\n"); + } else { + printf("Invalid Chat Channel number.\n"); + } + } else if (strlen(command) == 4 && command[0] == '/' && command[1] == 'l' && command[2] == 'c') { + printf("Chat Channels:\n"); + + for (int i = 0; i < MAXCHANNELS; i++) { + if (active[i] == 1) { + printf("\tChat Channel %d\n", i+1); + } + } + } else if (strlen(command) == 3 && command[0] == '/' && command[1] == 'q') { + printf("Quitting.\n"); + quit = true; + break; + } else if (strlen(command) == 3 && command[0] == '/' && command[1] == 'h') { + command_channel_help(); + } else { + printf("Invalid command.\n"); + } + + for (int i = 0; i < MAXCHANNELS; i++) { + if (active[i] == 2) { + pthread_join(channels[i], NULL); + close(pipes[i][0]); + close(pipes[i][1]); + active[i] = 0; + } + } + } + + for (int i = 0; i < MAXCHANNELS; i++) { + if (active[i] == 1 || active[i] == 2) { + pthread_join(channels[i], NULL); + } + } + + close(cpipe[0]); + close(cpipe[1]); + + return 0; +} |