Add a test script using pwntools

shell/Makefile

@@ -15,8 +15,5 @@ clean:
 	rm -f *.o sh core out
 	rm -r test-dir-*
 
-shell-test: shell-test.c
-	$(CC) -D_DEFAULT_SOURCE -Wall $< -o $@
-
-test: main shell-test
-	./shell-test `pwd`/$(OUT) -n
+test: main
+	python3 ./shell-test.py ./$(OUT)

shell/shell-test.py

+from pwn import *
+import time
+
+# timeout is in seconds, 1s would be enough for the "default" case
+def test_cmd(cmd, expstr=[], lines=1, timeout=1, mintime=None):
+	# print(cmd)
+	p.sendline(cmd)
+
+	t0 = time.time()
+	if expstr != []:
+		outstr = p.readlines(numlines=lines, timeout=timeout)
+
+	t1 = time.time()
+	# discard the rest of the output
+	p.clean(0)
+
+	# verify whether the command finished too early
+	if mintime and (t1 - t0) < mintime:
+		log.failure(f"Test for {cmd} failed: The command finished earlier than expected.")
+		return False
+
+
+	# expect empty result
+	if expstr == []:
+		log.success(f"Test for {cmd} passed.")
+		return True
+
+	# output number of lines is different
+	if len(expstr) != len(outstr):
+		log.failure(f"Test for {cmd} failed: Expected {expstr} but got {outstr}")
+		return False
+
+	for ous, exs in zip(outstr, expstr):
+		ous = ous.strip().decode()
+		if (exs not in ous):
+			log.failure(f"Test for {cmd} failed: Expected {exs} but got {ous}")
+			return False
+	log.success(f"Test for {cmd} passed.")
+	return True
+
+if __name__ == "__main__":
+	if len(sys.argv) != 2:
+		log.error(f"Run as f{sys.argv[0]} SHELL_EXEC")
+	else:
+		shell_exec = os.path.abspath(sys.argv[1])
+		with tempfile.TemporaryDirectory() as tmpdir:
+			os.chdir(tmpdir)
+			log.info(f"Working in {tmpdir}")
+			elf = ELF(shell_exec, checksec=False)
+			p = elf.process()
+
+			test_cmd('pwd', [tmpdir])
+			test_cmd('/bin/pwd', [tmpdir])
+			test_cmd('echo Hello!', ['Hello!'])
+			test_cmd('ls -a',['.  ..'])
+			test_cmd('touch file1.txt')
+			test_cmd('touch file1.txt; ls', ['file1.txt'])
+			test_cmd('echo world &',['world'])
+			# test_cmd('echo hello && echo world',['hello','world'],lines=2)
+			# test_cmd('sleep 3 && echo world &',['world'],lines=2,timeout=1)
+			test_cmd('sleep 3 ; echo hello', ['hello'],timeout=4,mintime=3)
+			test_cmd('echo Hi > file2.txt')
+			test_cmd('cat < file2.txt', ['Hi'])
+			test_cmd('cat < file2.txt > file3.txt; cat file3.txt',['Hi'])
+			test_cmd('cat file2.txt | wc -l',['1'])
+			test_cmd('cat file2.txt | cat | cat | cat | cat | wc -l',['1'])
+			test_cmd('echo 1 && echo 2',['1','2'], lines=2)
+			test_cmd('echo x | cat | wc -l && echo 2', ['1','2'], lines=2)
+			test_cmd('sleep 2; echo Done',['Done'],timeout=3)
+			test_cmd('cd /home; cd -; pwd',[tmpdir,tmpdir], lines=2)
+			test_cmd('cd /home; cd -; cd -; cd -',[tmpdir,'/home',tmpdir], lines=3)
+			test_cmd('cd .; pwd',[tmpdir])
+			test_cmd(f'cd /home; cd ..; pwd; cd {tmpdir}',['/'])
+			test_cmd(f'cd /home; cd ..; cd ..; cd ..; pwd; cd {tmpdir}',['/'])