int eval_node_pipe(NodeType *pn) {
NodeType *cmd1 = pipe_cmd(pipe_pipe(pn));
NodeType *cmd2 = pipe_cmd(pn);
pid_t pid1;
if ((pid1 = fork()) < 0) {
err_sys("fork error");
} else if (pid1 == 0) { // child
pid_t pid2;
int fd[2];
if (pipe(fd) < 0) err_sys("pipe failed");
if ((pid2 = fork()) < 0) {
err_sys("fork error");
return -1;
} else if (pid2 == 0) { // child
close(STDOUT_FILENO);
dup(fd[1]); // fd[1] is the write end, This call dup fd[1] to stdout
close(fd[0]);
close(fd[1]);
// write to stdout
return eval_cmd_in_proc(cmd1); // output of cmd1 will directed to pipe write end
} else { // parent
close(STDIN_FILENO);
dup(fd[0]); // fd[0] is the read end.
close(fd[0]);
close(fd[1]);
// read from(stdin) an empty pipe blocks reader.
return eval_cmd_in_proc(cmd2);
}
} else { // parent
if (waitpid(pid1, NULL, 0) < 0) {
err_sys("wait error");
}
}
return 0;
}
int main(int argc, char *argv[]){
char *argv[argc], *cmd1[argc], *cmd2[argc];
/*separate the commands in two*/
pipe_cmd(cmd1, cmd2);
}
int and_or_cmd (CMD *cmd)
{
int status = SUCCESS;
if (!cmd) return status;
if (cmd->type != SEP_AND && cmd->type != SEP_OR)
status = pipe_cmd(cmd);
else if (cmd->type == SEP_OR)
{
status = and_or_cmd(cmd->left);
if (status == ERROR) //short circuit otherwise
status = pipe_cmd(cmd->right);
}
else if (cmd->type == SEP_AND)
{
status = and_or_cmd(cmd->left);
if (status == SUCCESS)
status = pipe_cmd(cmd->right);
}
return status;
}
int main( int argc, char **argv ) {
pipe_cmd();
return 0;
}
int main(int argc, char *argv[])
{
char cmd [MAXCMD];
char* arg [MAXARG];
int* arg_count = new int(0),
* current_count = new int(0);
char the_path[256];
getcwd(the_path, 255);
name_shell(the_path);
signal(SIGINT, signalHandler);
system("clear");
do
{
strcpy(cmd , ""); //clears the input (solves a problem I was having).
printf("%s", shell_name.c_str()); //reprint shell name
std::cin.getline(cmd, MAXCMD, '\n'); // get input
parse(cmd, arg, arg_count);
// Only processes stuff that was entered into the shell
if(strcmp(cmd, "\0") != 0)
{
if(is_there_next_pipe(arg, *current_count, *arg_count))
{
// TODO: Fix handling more than one pipe
process_pipe(current_count);
// seperate commands for piping
char *cmd1[MAXARG], *cmd2[MAXARG];
// Left program
for(int i=0;i<*current_count;++i)
{
cmd1[i] = arg[i];//cmd1[i] = arg[i];
}
// Right program
for(int i=*current_count;i<*arg_count;++i)
{
cmd2[i-(*current_count)] = arg[i];//cmd2[i-(*current_count)] = arg[i-(*current_count)];
}
pipe_cmd(cmd1, cmd2);
//printf("Pipe: %s into %s\n", arg[*current_count-2], arg[*current_count]);
}
// Check if these are internal commands, which do not need forking
else if(is_internal_cmd(cmd))
process_internal_cmd(cmd, arg);
// Run process
else
run_cmd(arg, arg_count);
}
} while(true); // "exit" will stop the shell
return 0;
}