int main(int argc, char **argv) {
char commandBuf[BUFSIZE + 1];
struct Process proc;
char path[BUFSIZE + 1] = DEFAULT_PATH;
char *command;
int detached;
/* Set attribute to gray on black. */
Print("\x1B[37m");
while (true) {
/* Print shell prompt (bright cyan on black background) */
Print("\x1B[1;36m$\x1B[37m ");
/* Read a line of input */
Read_Line(commandBuf, sizeof(commandBuf));
command = Strip_Leading_Whitespace(commandBuf);
Trim_Newline(command);
detached = isDetached(command);
/*
* Handle some special commands
*/
if (strcmp(command, "exit") == 0) {
/* Exit the shell */
break;
} else if (strcmp(command, "pid") == 0) {
/* Print the pid of this process */
Print("%d\n", Get_PID());
continue;
} else if (strcmp(command, "exitCodes") == 0) {
/* Print exit codes of spawned processes. */
exitCodes = 1;
continue;
} else if (strncmp(command, "path=", 5) == 0) {
/* Set the executable search path */
strcpy(path, command + 5);
continue;
} else if (strcmp(command, "") == 0) {
/* Blank line. */
continue;
}
proc.command = Strip_Leading_Whitespace(command);
if (!Copy_Token(proc.program, proc.command)) {
Print("Error: invalid command\n");
continue;
}
Spawn_Single_Command(&proc, path, detached);
if (detached && proc.pid > 0)
Print("[%d]\n", proc.pid);
}
Print_String("DONE!\n");
return 0;
}
int main(int argc, char **argv)
{
int nproc;
char commandBuf[BUFSIZE+1];
struct Process procList[MAXPROC];
char path[BUFSIZE+1] = DEFAULT_PATH;
char *command;
/* Set attribute to gray on black. */
Print("\x1B[37m");
while (true) {
/* Print shell prompt (bright cyan on black background) */
Print("\x1B[1;36m$\x1B[37m ");
/* Read a line of input */
Read_Line(commandBuf, sizeof(commandBuf));
command = Strip_Leading_Whitespace(commandBuf);
Trim_Newline(command);
/*
* Handle some special commands
*/
if (strcmp(command, "exit") == 0) {
/* Exit the shell */
break;
} else if (strcmp(command, "pid") == 0) {
/* Print the pid of this process */
Print("%d\n", Get_PID());
continue;
} else if (strcmp(command, "exitCodes") == 0) {
/* Print exit codes of spawned processes. */
exitCodes = 1;
continue;
} else if (strncmp(command, "path=", 5) == 0) {
/* Set the executable search path */
strcpy(path, command + 5);
continue;
} else if (strcmp(command, "") == 0) {
/* Blank line. */
continue;
}
/*
* Parse the command string and build array of
* Process structs representing a pipeline of commands.
*/
nproc = Build_Pipeline(command, procList);
if (nproc <= 0)
continue;
Spawn_Pipeline(procList, nproc, path);
}
Print_String("DONE!\n");
return 0;
}
/*
* Build process pipeline.
*/
int Build_Pipeline(char *command, struct Process procList[])
{
int nproc = 0, i;
while (nproc < MAXPROC) {
struct Process *proc = &procList[nproc];
char *p, *s;
proc->flags = 0;
command = Strip_Leading_Whitespace(command);
p = command;
if (strcmp(p, "") == 0)
break;
++nproc;
s = strpbrk(p, "<>|");
/* Input redirection from file? */
if (s != 0 && *s == '<') {
proc->flags |= INFILE;
*s = '\0';
p = s+1;
s = Copy_Token(proc->infile, p);
if (s == 0) {
Print("Error: invalid input redirection\n");
return -1;
}
p = s;
/* Output redirection still allowed for this command. */
p = Strip_Leading_Whitespace(p);
s = (*p == '>' || *p == '|') ? p : 0;
}
/* Output redirection to file or pipe? */
if (s != 0 && (*s == '>' || *s == '|')) {
bool outfile = (*s == '>');
proc->flags |= (outfile ? OUTFILE : PIPE);
*s = '\0';
p = s+1;
if (outfile) {
s = Copy_Token(proc->outfile, p);
if (s == 0) {
Print("Error: invalid output redirection\n");
return -1;
}
p = s;
}
}
proc->command = command;
/*Print("command=%s\n", command);*/
if (!Copy_Token(proc->program, command)) {
Print("Error: invalid command\n");
return -1;
}
if (p == command)
command = "";
else
command = p;
}
if (strcmp(command,"") != 0) {
Print("Error: too many commands in pipeline\n");
return -1;
}
#if 0
for (i = 0; i < nproc; ++i) {
struct Process *proc = &procList[i];
Print("program=%s, command=\"%s\"\n", proc->program, proc->command);
if (proc->flags & INFILE)
Print("\tinfile=%s\n", proc->infile);
if (proc->flags & OUTFILE)
Print("\toutfile=%s\n", proc->outfile);
if (proc->flags & PIPE)
Print("\tpipe\n");
}
#endif
/*
* Check commands for validity
*/
for (i = 0; i < nproc; ++i) {
struct Process *proc = &procList[i];
if (i > 0 && (proc->flags & INFILE)) {
Print("Error: input redirection only allowed for first command\n");
return -1;
}
if (i < nproc-1 && (proc->flags & OUTFILE)) {
Print("Error: output redirection only allowed for last command\n");
return -1;
}
if (i == nproc-1 && (proc->flags & PIPE)) {
Print("Error: unterminated pipeline\n");
return -1;
}
}
return nproc;
}
