[fs/mode2octal] New AWK script to convert mode strings to octal

lib/fs/mode2octal.awk

@@ -0,0 +1,12 @@
+{
+	k = 0
+	m = substr($0, 1, 10)
+	for (i = 8; i >= 0; --i) {
+		c = substr(m, 10-i, 1)
+		k += ((c~/[rwxst]/)*2^i)
+		if ((i % 3) == 0) {
+			k += (tolower(c)~/[st]/)*2^(9+i/3)
+		}
+	}
+	printf("%04o" ORS, k)
+}

spec/fs/mode2octal.spec

@@ -0,0 +1,78 @@
+Describe 'fs/mode2octal'
+  EnableSandbox
+
+  SetupCommandFromFile mode2octal lib/fs/mode2octal.awk
+
+  modes_txt=${SHELLSPEC_SPECFILE%/*}/modes.txt
+
+  make_random_subset() {
+    rand_modes_txt="${SHELLSPEC_WORKDIR:?}/rand_modes.txt"
+    pick_random_lines 10% "${modes_txt}" >"${rand_modes_txt}"
+  }
+  BeforeAll 'make_random_subset'
+
+  It "converts plain mode strings to the correct octal values"
+
+    test_func() {
+      @awk -F'\t' '{ print $2 }' <"${rand_modes_txt}" \
+      | mode2octal
+    }
+
+    When call test_func
+
+    check_output() {
+      exec 7<"${rand_modes_txt}"
+
+      while read -r _oct_is
+      do
+        read -r _oct_should _string <&7
+
+        test "${_oct_is}" = "${_oct_should}" || {
+          printf 'mode string %s was converted to %s (but expected %s)\n' \
+                 "${_string}" "${_oct_is}" "${_oct_should}"
+        }
+      done <<EOF
+$1
+EOF
+
+      exec 7>&-
+    }
+
+    The status should be success
+    The result of function check_output should equal ''
+    The stderr should equal ''
+  End
+
+
+  It "converts ls(1) long output to the correct octal values"
+
+    test_func() {
+      @awk -F'\t' '{ printf "%s 1 nobody nogroup 0 Jan  1  1970 %s"ORS, $2, $1 }' <"${rand_modes_txt}" \
+      | mode2octal
+    }
+
+    When call test_func
+
+    check_output() {
+      exec 7<"${rand_modes_txt}"
+
+      while read -r _oct_is
+      do
+        read -r _oct_should _string <&7
+
+        test "${_oct_is}" = "${_oct_should}" || {
+          printf 'mode string %s was converted to %s (but expected %s)\n' \
+                 "${_string}" "${_oct_is}" "${_oct_should}"
+        }
+      done <<EOF
+$1
+EOF
+
+      exec 7>&-
+    }
+
+    The status should be success
+    The result of function check_output should equal ''
+    The stderr should equal ''
+  End
+End