void analyseCommand(char *cmd) {
char *program = NULL;
int start, end;
int canExecute = 0;
if(setExpressionDelimiters(cmd, "^( *[^&<> ]+)+", &start, &end)) {
/* command begins from the start */
program = getExpression(cmd, start, end, 0);
canExecute = 1;
} else if (setExpressionDelimiters(cmd, "[^<> ] ( *[^<> ]+)+", &start, &end)) {
/* command begins from somewhere else */
program = getExpression(cmd, start, end, 1);
canExecute = 1;
}
if(!canExecute) {
exit(EXIT_FAILURE);
}
if(redirectInput(cmd)) {
exit(EXIT_FAILURE);
}
redirectOutput(cmd);
free(cmd);
executeProgram(program);
}
/******************************************************
Tries to redirect, fork, and execute the job passed
to the method. This method is designed to work with
two pipes, so it should not be used for the first
and last jobs in the pipeline.
PRE: The necessary pipes have already been created
and file descriptor array pointers are stored
in the vector pipe_fds.
POST: Returns true in the parent if successful. Nothing
is returned on success in the child. Returns false
if an error was encountered.
*/
bool PipeManager::createMiddleChild(int command_index) {
// linux system call
int pid = fork();
// error checking
if (pid == -1) {
cout << "Execution error: " << endl;
cout << " Could not create process." << endl;
return false;
}
// child code
if (pid == 0) {
// figure out which pipes we're using
int out_pipe = command_index;
int in_pipe = command_index - 1;
redirectInput(pipe_fds[in_pipe][0]); // read end of the pipe
close(pipe_fds[in_pipe][1]);
redirectOutput(pipe_fds[out_pipe][1]); // write end of pipe
close(pipe_fds[out_pipe][0]);
// close all other pipes
for (int closePtr = 0; closePtr < pipe_fds.size(); closePtr++) {
if ((closePtr != in_pipe) && (closePtr != out_pipe)) {
//linux system calls
close(pipe_fds[closePtr][0]);
close(pipe_fds[closePtr][1]);
}
}
// replace process code with the given job
callExec(command_index);
}
// still here, must be in parent
pids.push_back(pid);
return true;
}
/******************************************************
Tries to redirect, fork, and execute the last job in
the piped command.
PRE: The necessary pipes have already been created
and file descriptor array pointers are stored
in the vector pipe_fds.
POST: Returns true in the parent if successful. Nothing
is returned on success in the child. Returns false
if an error was encountered.
*/
bool PipeManager::createLastChild() {
// linux system call
int pid = fork();
// error checking
if (pid == -1) {
cout << "Execution error: " << endl;
cout << " Could not create process." << endl;
return false;
}
// child code
if (pid == 0) {
// figure out which pipe we're using
int my_pipe = pipe_fds.size() - 1;
close(pipe_fds[my_pipe][1]); // we don't want to write to pipe
redirectInput(pipe_fds[my_pipe][0]); // read end of the pipe
// close all other pipes
for (int closePtr = 0; closePtr < pipe_fds.size(); closePtr++) {
if (closePtr != my_pipe) {
//linux system calls
close(pipe_fds[closePtr][0]);
close(pipe_fds[closePtr][1]);
}
}
// replace process code with last job
callExec(my_command.getCommands().size() - 1);
}
// still here, must be in parent
pids.push_back(pid);
return true;
}
int main(int argc, char *argv[]){
char *line;
pipeline pl;
int run;
//flags
int redo = 0;
int skip = 0;
int isResume = 0;
char *promptstr;
char* buffer;
numExits = 0;
jobIndex = 0;
histIndex = 0;
back = 0;
script = 0;
FILE* in;
/* check for the right number of arguments */
//if ( argc > 2 ) {
// printusage(argv[0]);
// exit(-1);
//}
if (argc >= 2)
{
DIR* dirp;
struct dirent *dp;
int isFound = 0;
if ((dirp = opendir(".")) == NULL)
{
perror("couldn't open path");
return 0;
}
//put files into array and sort their names
while ((dp = readdir(dirp)) != NULL)
{
if (strcmp(dp->d_name, argv[1]) == 0)
{
isFound = 1;
}
}
if (isFound == 0)
{
printf("%s: Command not found\n", argv[1]);
}
else
{
in = fopen(argv[1], "r");
buffer = (char*)malloc(sizeof(in));
script = 1;
}
}
//struct termios saved_term_mode;
struct sigaction action;
action.sa_handler = killHandle; /* set tick to be the handler function */
sigemptyset(&action.sa_mask); /* clear out masked functions */
action.sa_flags = 0; /* no special handling */
struct sigaction action2;
action2.sa_handler = susHandle; /* set tick to be the handler function */
sigemptyset(&action2.sa_mask); /* clear out masked functions */
action2.sa_flags = 0; /* no special handling */
/*
* Use the sigaction function to associate the signal action with SIGALRM.
*/
if (sigaction(SIGINT, &action, NULL) < 0 ) {
fprintf(stderr, "SIGINT\n");
exit(-1);
}
if(sigaction(SIGTSTP, &action2, NULL) < 0) {
fprintf(stderr, "SIGTSTP\n");
exit(-1);
}
//saved_term_mode = set_raw_term_mode();
initHistory();
initJobs();
//strcpy(jobs[1], "hey");
/* set prompt */
promptstr = PROMPT;
run = TRUE;
if (script == 0)
prompt(promptstr);
while ( run )
{
/// if reexecute was not called
if (redo == 0)
{
if (script == 0)
{
if ( NULL == (line = readLongString(stdin)) )
{
if ( feof(stdin) )
run = FALSE;
}
}
else
{
fgets(line, sizeof(in), in);
if (line[0] == '%')
{
line++;
isResume = 1;
}
}
}
else
{
//printf("histInd: %d\n", histIndex);
///if reexecute was called,
///find the correct place in the history
///list to extract the reexecuted command
int temp = histIndex;
temp--;
int ind = 0;
while (ind != reNumber)
{
temp--;
ind++;
}
line = history[temp];
printf("%s\n", line);
}
if (line == NULL)
{
if (feof(stdin))
run = FALSE;
}
else
{
if (line[0] == '%')
{
line++;
isResume = 1;
}
/* We got a line, send it off to the pipeline cracker and
* launch it
*/
//if (redo == 0)
//{
pl = crack_pipeline(line);
//}
redo = 0;
/*
* Show that it worked. This is where you're going to do
* something radically different: rather than printing the
* pipeline, you're going to execute it.
*/
if ( pl != NULL && strlen(pl->cline) > 0)
{
/*
if (pl->cline[0] == '%')
{
int i;
isResume = 1;
pl->stage[0].argv[0][0] = ' ';
for (i = 0; i < strlen(pl->cline)-1; i++)
{
pl->stage[0].argv[0][i] = pl->stage[0].argv[0][i+1];
}
pl->stage[0].argv[0][strlen(pl->cline)-1] = '\0';
}
*/
//print_pipeline(stdout,pl); /* print it. */
addHistory(pl->cline);
///add to the history what was typed into the command line
if (strcmp(pl->stage[0].argv[0], "history") == 0)
{
///print the history if possible
if (pl->stage[0].argc > 1)
{
printf("Junk after built-in command\n");
skip = 1;
}
numExits = 0;
if (skip == 0)
printHistory();
skip = 0;
}
else if (strcmp(pl->stage[0].argv[0], "jobs") == 0)
{
///print the suspended jobs if possible
if (pl->stage[0].argc > 1)
{
printf("Junk after built-in command\n");
skip = 1;
}
numExits = 0;
if (skip == 0)
printJobs();
skip = 0;
}
else if (strcmp(pl->stage[0].argv[0], "exit") == 0)
{
///exit vssh if possible
if (pl->stage[0].argc > 1)
{
fprintf(stderr, "Junk after built-in command\n");
skip = 1;
}
numExits++;
if (skip == 0)
exitCmd();
skip = 0;
}
else if (strcmp(pl->stage[0].argv[0], "bg") == 0)
{
///background the most recently suspended job if possible
if (pl->stage[0].argc > 1)
{
fprintf(stderr, "Junk after built-in command\n");
skip = 1;
}
numExits = 0;
if (skip == 0)
bg(jobs[jobIndex-1]);
skip = 0;
}
else if (strcmp(pl->stage[0].argv[0], "fg") == 0)
{
///foreground the most recently backgrounded job if possible
if (pl->stage[0].argc > 1)
{
fprintf(stderr, "Junk after built-in command\n");
skip = 1;
}
numExits = 0;
if (skip == 0)
fg(jobs[jobIndex-1]);
skip = 0;
}
else if (strcmp(pl->stage[0].argv[0], "cd") == 0)
{
///change the directory of vssh if possible
if (pl->stage[0].argc > 2)
{
fprintf(stderr, "Junk after built-in command\n");
skip = 1;
}
numExits = 0;
if (skip == 0)
cd(pl->stage[0].argv[1]);
skip = 0;
}
else if (isResume == 1)
{
///foreground the specified job if possible
if (pl->stage[0].argc > 1)
{
fprintf(stderr, "Junk after built-in command\n");
skip = 1;
}
numExits = 0;
if (skip == 0)
{
//pl->stage[0].argv[0]++;
int i;
int killFlag = 0;
for (i = 0; i < strlen(pl->stage[0].argv[0]); i++)
{
if (!isdigit(pl->stage[0].argv[0][i]))
{
///if the supplied job number is not a number
///then print error
killFlag = 1;
fprintf(stderr, "%s: No such job.\n", pl->stage[0].argv[0]);
}
}
if (killFlag == 0)
{
if (atoi(pl->stage[0].argv[0]) <= 0 || atoi(pl->stage[0].argv[0]) > jobIndex)
///if the supplied job number is not a valid job index
///then print error
fprintf(stderr, "%s: No such job.\n", pl->stage[0].argv[0]);
else
resume(jobs[atoi(pl->stage[0].argv[0])-1]->id, atoi(pl->stage[0].argv[0])-1);
}
}
skip = 0;
}
else if (strcmp(pl->stage[0].argv[0], "!") == 0)
{
///reexecute the specified history command if possible
if (pl->stage[0].argc > 2 || strlen(pl->stage[0].argv[1]) > 3)
{
fprintf(stderr, "Junk after built-in command\n");
skip = 1;
}
///if the number supplied is not a valid history index
///then print error
if (pl->stage[0].argv[1][0] == '0' && skip == 0)
{
fprintf(stderr, "%s: Event not found\n", pl->stage[0].argv[1]);
skip = 1;
}
if (strlen(history[atoi(pl->stage[0].argv[1])]) <= 0 && skip == 0)
{
fprintf(stderr, "%s: Event not found\n", pl->stage[0].argv[1]);
skip = 1;
}
int i;
for (i = 0; i < strlen(pl->stage[0].argv[1]); i++)
{
if (!isdigit(pl->stage[0].argv[1][i]) && skip == 0)
{
///if the number supplied is not a number
///then print error
fprintf(stderr, "%s: Event not found\n", pl->stage[0].argv[1]);
skip = 1;
}
}
numExits = 0;
if (skip == 0)
{
redo = 1;
reNumber = atoi(pl->stage[0].argv[1]);
//printf("renum: %d\n", reNumber);
//pl = crack_pipeline(history[atoi(pl->stage[0].argv[1])]);
//printf("%s\n", pl->cline);
//lineno++;
//continue;
}
skip = 0;
}
else if (strcmp(pl->stage[0].argv[0], "kill") == 0)
{
///kill the specified job if possible
if (pl->stage[0].argc > 2)
{
fprintf(stderr, "Junk after built-in command\n");
skip = 1;
}
numExits = 0;
if (skip == 0)
{
int i;
int killFlag = 0;
for (i = 0; i < strlen(pl->stage[0].argv[1]); i++)
{
///if the supplied job number is not a number
///then print error
if (!isdigit(pl->stage[0].argv[1][i]))
{
killFlag = 1;
fprintf(stderr, "%s: No such job.\n", pl->stage[0].argv[1]);
}
}
if (killFlag == 0)
{
if (atoi(pl->stage[0].argv[1]) <= 0 || atoi(pl->stage[0].argv[1]) > jobIndex)
///if the supplied job number is not a valid job index
///then print error
fprintf(stderr, "%s: No such job.\n", pl->stage[0].argv[1]);
else
killProcess(atoi(pl->stage[0].argv[1])-1, jobs[atoi(pl->stage[0].argv[1])-1]->id);
}
}
skip = 0;
}
else
{
///pipe/redirect as necessary
numExits = 0;
//int i;
//for (i = 0; i < pl->length; i++)
//{
//else
//{
//handle backgrounding "&"
//find the &
int j;
int andFound = 0;
int pipeFound = 0;
for (j = 1; j < strlen(pl->cline); j++)
{
if (pl->cline[j] == '|')
{
//fprintf(stderr, "Pipelines cannot be backgrounded\n");
pipeFound = 1;
}
else if (pl->cline[j] == '&')
{
//error if & is not the last arg, exec nothing
if (pipeFound == 1)
{
fprintf(stderr, "Pipelines cannot be backgrounded\n");
}
else if (j != strlen(pl->cline) - 1)
{
andFound = 1;
fprintf(stderr, "Junk after '&'.\n");
}
else if (pl->cline[j-1] == ' ')
{
andFound = 1;
pl->cline[j] = '\0';
//backExec(pl->stage[0].argv[0], pl->stage[0].argv, pl->cline);
back = 1;
}
}
}
if (pl->length >= 2)
{
///pipe if the pipline has 2 or more stages
pipeCmd(pl);
}
else if (pl->stage[0].outname != NULL && pl->stage[0].inname != NULL)
{
redirectBoth(pl->stage[0].argv, pl->stage[0].inname, pl->stage[0].outname);
}
else if (pl->stage[0].outname != NULL)
{
///otherwise redirect output if there is an outfile
redirectOutput(pl->stage[0].argv, pl->stage[0].outname, pl->cline);
}
else if (pl->stage[0].inname != NULL)
{
///otherwise redirect input if there is an infile
redirectInput(pl->stage[0].argv, pl->stage[0].inname, pl->cline);
}
else if (andFound == 0)
{
//execute if not a built-in command
execute(pl->stage[0].argv[0], pl->stage[0].argv, pl->cline);
}
back = 0;
//}
//}
}
}
free_pipeline(pl);
fflush(stdout); /* also frees line */
lineno++; /* readLongString trims newlines, so increment it manually */
}
if (run )
{
if (script == 0) /* assuming we still want to run */
prompt(promptstr);
}
}
return 0;
}
