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#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/wait.h>
#include "syntax.h"
#include "utils.h"
void execute_command_pipeline(Pipeline pipeline, int stdin_fd, int stdout_fd);
void execute_cmd(ExecutableCommand cmd, int* pgid) {
pid_t pid = fork();
if (pid == 0) {
if (*pgid == -1) {
setpgid(0, 0);
} else {
setpgid(0, *pgid);
}
dup2(cmd.stdin_fd, STDIN_FILENO);
dup2(cmd.stdout_fd, STDOUT_FILENO);
for (int i = 0; i < cmd.redirects.count; i++) {
FdRedirect fd_rd = *get_from_FdRedirectVec(&cmd.redirects, i);
dup2(fd_rd.to, fd_rd.redirected);
}
for (int j = 0; j < cmd.child_open_fds.count; j++) {
int fd = *get_from_IntVec(&cmd.child_open_fds, j);
close(fd);
}
signal(SIGINT, SIG_DFL);
signal(SIGQUIT, SIG_DFL);
signal(SIGTSTP, SIG_DFL);
signal(SIGTTIN, SIG_DFL);
signal(SIGTTOU, SIG_DFL);
execvp(cmd.args[0], cmd.args);
exit(67);
}
if (*pgid == -1) {
setpgid(pid, pid);
*pgid = pid;
} else {
setpgid(pid, *pgid);
}
}
ExecutableCommand process_pl_command(PlCommand pl_cmd) {
StrVec arg_vec = make_StrVec(256);
FdRedirectVec fd_redirs = make_FdRedirectVec(256);
IntVec parent_open_fds = make_IntVec(256);
IntVec child_open_fds = make_IntVec(256);
int ps_pipe_fds[2];
for (int i = 0; i < pl_cmd.args.count; i++) {
Arg arg = *get_from_ArgVec(&pl_cmd.args, i);
switch (arg.kind) {
case ARG_LIT:
push_to_StrVec(&arg_vec, arg.as.lit_str);
break;
case ARG_PS_IN:
pipe(ps_pipe_fds);
execute_command_pipeline(*(Pipeline*)arg.as.sub_pipeline, STDIN_FILENO, ps_pipe_fds[1]);
close(ps_pipe_fds[1]);
char pname[64];
snprintf(pname, sizeof(pname), "/dev/fd/%d", ps_pipe_fds[0]);
push_to_IntVec(&parent_open_fds, ps_pipe_fds[0]);
push_to_StrVec(&arg_vec, strdup(pname));
break;
default:
exit(67);
}
}
for (int j = 0; j < pl_cmd.redirects.count; j++) {
Redirect redir = *get_from_RedirectVec(&pl_cmd.redirects, j);
FdRedirect fd_redir;
int fd;
switch (redir.kind) {
case REDIR_READ:
fd = open(redir.as.filename, O_RDONLY, 0644);
push_to_IntVec(&parent_open_fds, fd);
push_to_IntVec(&child_open_fds, fd);
fd_redir = (FdRedirect){.to = fd, .redirected = STDIN_FILENO};
break;
case REDIR_WRITE_APPEND:
fd = open(redir.as.filename, O_WRONLY | O_CREAT | O_APPEND, 0644);
push_to_IntVec(&parent_open_fds, fd);
push_to_IntVec(&child_open_fds, fd);
fd_redir = (FdRedirect){.to = fd, .redirected = STDOUT_FILENO};
break;
case REDIR_WRITE_TRUNC:
fd = open(redir.as.filename, O_WRONLY | O_CREAT | O_TRUNC, 0644);
push_to_IntVec(&parent_open_fds, fd);
push_to_IntVec(&child_open_fds, fd);
fd_redir = (FdRedirect){.to = fd, .redirected = STDOUT_FILENO};
break;
default:
exit(67);
}
push_to_FdRedirectVec(&fd_redirs, fd_redir);
}
char** args = malloc(sizeof(char*) * (arg_vec.count + 1));
for (int i = 0; i < arg_vec.count; i++) {
args[i] = *get_from_StrVec(&arg_vec, i);
}
args[arg_vec.count] = NULL;
return (ExecutableCommand){.args = args, .redirects = fd_redirs, .parent_open_fds = parent_open_fds, .child_open_fds = child_open_fds};
}
void execute_command_pipeline(Pipeline pipeline, int stdin_fd, int stdout_fd) {
int trunk_fd = stdin_fd;
int pgid = -1;
for (int i = 0; i < pipeline.count; i++) {
PlCommand cmd = *get_from_Pipeline(&pipeline, i);
ExecutableCommand exec_cmd = process_pl_command(cmd);
exec_cmd.stdin_fd = trunk_fd;
if (i > 0) {
push_to_IntVec(&exec_cmd.parent_open_fds, trunk_fd);
push_to_IntVec(&exec_cmd.child_open_fds, trunk_fd);
}
exec_cmd.stdout_fd = stdout_fd;
if (cmd.conn == CONN_PIPE) {
int pipe_fds[2];
pipe(pipe_fds);
exec_cmd.stdout_fd = pipe_fds[1];
push_to_IntVec(&exec_cmd.parent_open_fds, pipe_fds[1]);
push_to_IntVec(&exec_cmd.child_open_fds, pipe_fds[1]);
trunk_fd = pipe_fds[0];
}
execute_cmd(exec_cmd, &pgid);
for (int j = 0; j < exec_cmd.parent_open_fds.count; j++) {
int fd = *get_from_IntVec(&exec_cmd.parent_open_fds, j);
close(fd);
}
}
tcsetpgrp(STDIN_FILENO, pgid);
while (waitpid(-pgid, NULL, 0) > 0);
tcsetpgrp(STDIN_FILENO, getpgrp());
}
void execute_pipeline_tree(PipelineTree pltree) {
signal(SIGTTIN, SIG_IGN);
signal(SIGTTOU, SIG_IGN);
execute_command_pipeline(*pltree.root, STDIN_FILENO, STDOUT_FILENO);
}
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