I'm not sure what's going on but I've been trying to understand what is happening with the input and output. So here is my program.
#include <stdio.h> #include <stdlib.h> int main(){ char pass[8]; fgets(pass, 8, stdin); if (pass[1] == 'h'){ printf("enter shell\n"); system("/bin/bash"); printf("leave shell\n"); } return 0; } And here are some terminal commands. When I run it regularly, and input 'hh', the shell stays opened.
idkanything ~ $ ./a.out hh enter shell bash-3.2$ Now I try to echo then pipe, but the shell closes immediately.
idkanything ~ $ echo "hh" | ./a.out enter shell leave shell So now here is when it works:
idkanything ~ $ cat <(python -c 'print "hh"') - | ./a.out enter shell this work /bin/bash: line 1: this: command not found leave shell But when I leave out the '-' for stdin, it does not work as in the shell closes immediately.
idkanything ~ $ cat <(python -c 'print "hh"') | ./a.out enter shell leave shell When I have cat at the end here, it also works.
idkanything ~ $ (python -c 'print "hh"'; cat) | ./a.out enter shell this works /bin/bash: line 1: this: command not found leave shell Can someone please explain what's going on? What specifically about the commands that work makes the shell stay open? Why does the shell only stay open for these commands and not for the other commands like echoing "hh" and then piping that in.
I believe it may have something to do with stdout.
