+// test: echo -e '\t\t' | calc.exe | grep -q 'print'
+// test: echo -e '1 + 1;\nans + 1' | calc.exe | grep -qv 2
+// test: echo -e 'mem (3)\nsto (4, pi)' | calc.exe | grep -q "invalid index"
+// test: echo -e 'sto (2, 3)\nmem (2)\ndisp' | calc.exe | grep -q 'storage: 0 3$'
+// test: echo -e 'disp' | calc.exe | grep -q "storage: 0 0 0 0 0 0 0 0 0 0"
+// test: echo -e 'sto (3, 10)\ndisp' | calc.exe | grep -q "storage: 0 0 10 0 0 0 0 0 0 0"
+// test: echo -e 'rcl (3)\ndisp' | calc.exe | grep -q "storage: 0 0 0 0 0 0 0 0 0 0"
+// test: echo -e 'inc (2)\ndisp' | calc.exe | grep -q "storage: 0 1 0 0 0 0 0 0 0 0"
+// test: echo -e 'dec (2)\ndisp' | calc.exe | grep -q "storage: 0 -1 0 0 0 0 0 0 0 0"
+// test: echo -e 'sto (3, pi)\nclr\ndisp' | calc.exe | grep -q "storage: 0 0 0 0 0 0 0 0 0 0"
+// test: echo -e 'mem (3)\nclr\nquit' | calc.exe -v 3 | grep -q Clear
+// test: echo -e 'prog (2, {arg (2) - arg (1)})\nprog (1, {cos (arg (1)^2)})\ncall (1, pi/6)\nprog (2, {arg (1) * 3})\ncall (2, 1, 2)\nls' | calc.exe
+// test: echo -e 'prog (1, {arg (2) - arg (1)})\ncall (1, 2, 3)\nls\nedit (1)\nprog (1, {arg (2) + arg (1)})\nedit (1)\ndel (1)\nquit' | calc.exe -v 3 | grep -q bye
+// test: echo -e 'prog (2, {arg (2) - arg (1)})\nprog (3, cos(arg (1) * pi / 3))\ncall (1, 2, 3)\ncall (2, 1)\nls\nedit (1)\ndel (1)\n\ndel (2)\ncall (2, 1, 4)' | calc.exe | grep -c error | xargs test 5 =
+// test: echo -e 'erf (1)\nerfc (1)\nquit' | calc.exe -v 3 | grep -q bye
+// test: echo -e 'erf ()\nerfc ()' | calc.exe | grep -c error | xargs test 2 =
+// test: echo -e 'set (1, 2, 3, 3.11, pi, 4)\nget (4)' | calc.exe | grep '=> 3.11'
+// test: echo -e 'set (1, 2, 3, 3.11, pi, 4)\npop\npop\n5\npush\nshow' | calc.exe | grep 'stack: 1 2 3 3.11 5'
+// test: echo -e 'set (1, 2, 3, 3.11, pi, 4)\nset\nput (3, 4)\nshow' | calc.exe | grep 'stack: 0 0 4'
+// test: echo -e 'set (0, -1)\nset (1, 2, 3, 3.11, pi, 4)\nlen' | calc.exe | grep '=> 6'
+// test: echo -e 'set (1, 2)\npop\npush (3)\nput (5, -1)\nlen\nshow\nget (3)\nquit' | calc.exe -n -v 3 | grep -q bye
+// test: echo -e 'put\nget\nget (1)\npop\nput (0)' | calc.exe | grep -c 'error' | xargs test 5 =
+// test: echo -e 'prog (1, {set (1, 2), push (arg (1)), show})\ncall (1, 10)\nprog (1, {mem (1), sto (1, cos (arg (1)))})\ncall (1, pi / 2)\ndel (1)' | calc.exe -n | grep -q 'stack: 1 2 10'
+// test: echo -e 'prog (1, {set (1, 2), push (arg (1)), show});\ncall (1, 10);\nshow\ndel (1)' | calc.exe -n | grep -q 'stack:$'
+// test: echo -e 'prog (1, {set (1, 2), push (arg (1)), show});\ncall (1, 10);\nlen' | calc.exe -n | grep -q '=> 0'
+// test: echo -e 'prog (1, {mem (2), sto (1, arg (1) - rcl (1) / 2)})\ncall (1, 1)\ncall (1, 2)\ncall (1, 3)\nprog (1, {mem (2), sto (2, rcl (1)), sto (1, arg (1)), rcl (2)})\ncall (1, 10)' | calc.exe -n | grep -q '=> 2.25'
+// test: echo -e 'set (1, 2, -5, 6, -8, 9, -2, 23, 4)\nord\nshow' | calc.exe | grep -q 'stack: -8 -5 -2 1 2 4 6 9 23'
+// test: echo -e 'set (1, 2, -5, 6, -8, 9, -2, 23, 4)\nmin (5, -3)\nmax (-1)\nmean (1, 2)\nvar (1, 2)\nmin\nmean\nmed\nmax\nprod\nsum\nvar' | calc.exe | awk 'BEGIN { split("9 -3 -1 1.5 0.5 -8 3.33333 2 23 -794880 30 73.3333", v) } /=>/ { for (i in v) if ($2 == v[i]) n++ } END { exit n != 12 }'
+// test: echo -e 'set (1, 2, -5, 6, -8, 9, -2, 23, 4)\nmin (5, -3)\nmax (-1)\nmin\nmean\nmed\nmax\nord\nprod\nsum\nvar\nquit' | calc.exe -n -v 3 | grep bye
+// test: echo -e 'min\nmean\nmed\nmax\nprod\nsum\nvar\nord' | calc.exe -n | grep -c error | xargs test 8 =