This is some output from a run of my shell program. Anything after a # is a comment that I've added to explain what's going on.
cs31shell> ls
Makefile cs31shell parsecmd.c parsecmd.o sleeper tester
README.md cs31shell.c parsecmd.h sample_inputs sleeper.c tester.c
cs31shell> ls -l
total 112
-rw------- 1 kwebb users 448 Nov 1 10:15 Makefile
-rw-r--r-- 1 kwebb users 24 Nov 1 10:15 README.md
-rwxr-xr-x 1 kwebb users 23808 Nov 1 15:27 cs31shell
-rw------- 1 kwebb users 6542 Nov 1 15:27 cs31shell.c
-rw------- 1 kwebb users 1468 Nov 1 10:16 parsecmd.c
-rw------- 1 kwebb users 1468 Nov 1 10:15 parsecmd.h
-rw-r--r-- 1 kwebb users 7344 Nov 1 10:16 parsecmd.o
-rw-r--r-- 1 kwebb users 163 Nov 1 15:39 sample_inputs
-rwxr-xr-x 1 kwebb users 17440 Nov 1 10:16 sleeper
-rw------- 1 kwebb users 631 Nov 1 10:15 sleeper.c
-rwxr-xr-x 1 kwebb users 22008 Nov 1 10:16 tester
-rw------- 1 kwebb users 2456 Nov 1 10:15 tester.c
cs31shell> whoami
kwebb
cs31shell> ./sleeper &
cs31shell> ./sleeper &
cs31shell> ./sleeper 10 &
cs31shell> ps
PID TTY TIME CMD
2368939 pts/15 00:00:00 bash
2369011 pts/15 00:00:00 cs31shell
2369086 pts/15 00:00:00 sleeper
2369097 pts/15 00:00:00 sleeper
2369113 pts/15 00:00:00 sleeper
2369114 pts/15 00:00:00 ps
# Wait for some time to pass...
cs31shell> ps
PID TTY TIME CMD
2368939 pts/15 00:00:00 bash
2369011 pts/15 00:00:00 cs31shell
2369194 pts/15 00:00:00 ps
cs31shell> blah
blah: command not found
cs31shell> ps
PID TTY TIME CMD
2368939 pts/15 00:00:00 bash
2369011 pts/15 00:00:00 cs31shell
2369284 pts/15 00:00:00 ps
cs31shell> cd
cs31shell> pwd
/home/kwebb
cs31shell> cd cs31/weeklylab/week02
cs31shell> pwd
/home/kwebb/cs31/weeklylab/week02
cs31shell> ls
Makefile readfile.h testfile.c testprog.c types_scanf.c values2
readfile.c testfile testprog types_scanf values1
cs31shell> cd
cs31shell> pwd
/home/kwebb
cs31shell> exit
Bye!