static void Exec(commandT* cmd, bool forceFork)
{
pid_t child_pid;
sigset_t mask;
//empty out the masking set
sigemptyset(&mask);
//add child signal to the mask
sigaddset(&mask, SIGCHLD);
//block child signal
sigprocmask(SIG_BLOCK, &mask, NULL);
//fork the process
child_pid = fork();
fgpid = child_pid;
if(child_pid == 0)
{
//child process here
//put the child process in a new process group
//this group's id is the child's pid
setpgid(0, 0);
//execute child process
execv(cmd->name, cmd->argv);
//this should only display if the execution fails
fprintf(stdout, "Error executing child command: %s\n", cmd->cmdline);
}
else if(child_pid > 0)
{
//parent process here
last_cmd = cmd->cmdline;
if(cmd->bg)
{
//add to bg jobs
AddJobToBg(child_pid);
//unblock child signals
sigprocmask(SIG_UNBLOCK, &mask, NULL);
}
else
{
//unblock child signals
sigprocmask(SIG_UNBLOCK, &mask, NULL);
stopped = 0;
wait_fg();
}
//let us know that the parent passed
// fprintf(stdout, "Parent passed command: %s\n", cmd->cmdline);
}
else
{
fprintf(stdout, "Fork failed for command: %s\n", cmd->cmdline);
}
}
/* what >bg and >fg run */
void do_bgfg(char **cmd, int state)
{
jobs **job;
sigset_t msk;
MASK_SIG(SIG_BLOCK, SIGCHLD, msk);
if (!cmd[1]) {
job = get_lastjob();
}
else if (*cmd[1]=='%' && atoi(cmd[1]+1)) {
job = getjob(0, atoi(cmd[1]+1));
}
else {
ERRMSG("Invalid argument\n");
return;
}
/* thy shall NOT pass */
if (NOTNULL(job)) {
(*job)->state = state;
if (kill(-(*job)->pid[0], SIGCONT) < 0)
ERR_EXIT("kill");
if (state == BG) {
shell_printf(SHELLPRINT_CHKSS | SHELLPRINT_CHKTERM,
"[%d] (%d) %s\n", (*job)->jid, (*job)->pid[0], (*job)->cmdline);
}
else {
shell_printf(SHELLPRINT_CHKSS | SHELLPRINT_CHKTERM,
"%s\n", (*job)->cmdline);
wait_fg(job);
}
}
else {
ERRMSG("Invalid job\n");
}
/* thy shall pass */
MASK_SIG(SIG_UNBLOCK, SIGCHLD, msk);
}
static void RunBuiltInCmd(commandT* cmd)
{
// Execute cd
if(!strcmp(cmd->argv[0],"cd"))
{
if(cmd->argc==1)
{
int ret = chdir(getenv("HOME"));
if(ret == -1)
{
// fprintf(stdout, "Error changing directory with command: %s\n", cmd->cmdline);
}
}
else
{
int ret = chdir(cmd->argv[1]);
if(ret == -1)
{
// fprintf(stdout, "Error changing directory with command: %s\n", cmd->cmdline);
}
}
}
// Execute env variable assignments
else if (strchr(cmd->argv[0],'='))
{
char* var = strtok(cmd->argv[0],"=");
char* val = strtok(NULL,"=");
setenv(var,val,1);
}
// Execute bg
else if (strcmp(cmd->argv[0], "bg") == 0)
{
struct bgjob_l* jobPointer = bgjobs;
if(jobPointer != NULL)
{
// find most recent job
if(cmd->argc < 2)
{
while(jobPointer->next != NULL)
{
jobPointer = jobPointer->next;
}
}
else
{
int i; // find indicated job
printf("cmd-> argv[1] = %s\n", cmd->argv[1]);
printf("(int)*cmd->argv[1] = %d\n", (int)*cmd->argv[1]);
for(i = 1; i < (int)*cmd->argv[1]; i++)
{
jobPointer = jobPointer->next;
}
}
kill(jobPointer->pid, SIGCONT); // resume job
}
}
// Execute jobs
else if (strcmp(cmd->argv[0], "jobs") == 0)
{
struct bgjob_l* jobPointer = bgjobs;
int i = 1;
if(jobPointer != NULL)
{
while(jobPointer != NULL)
{
printf("[%d] %-24s%s%s\n", jobPointer->id, jobPointer->status, jobPointer->cmdline, strcmp(jobPointer->status, "Running") == 0 ? "&" : "");
fflush(stdout);
i++;
jobPointer = jobPointer->next;
}
removeCompletedJobs();
}
else
{
// fprintf(stdout, "jobPointer is null\n");
}
}
// Execute fg
else if (!strcmp(cmd->argv[0], "fg")){
struct bgjob_l* jobPointer = bgjobs;
// tcsetpgrp()???
if(jobPointer != NULL)
{
// find most recent job
if(cmd->argc < 2)
{
while(jobPointer->next != NULL)
{
jobPointer = jobPointer->next;
}
}
else
{ // find indicated job
int i;
for(i = 1; i < (int)*cmd->argv[1]; i++)
{
jobPointer = jobPointer->next;
}
}
fgpid = jobPointer->pid;
kill(jobPointer->pid, SIGCONT);
stopped = 0;
wait_fg();
RemoveJob(fgpid);
}
}
}
