Add escape module and tests

Author: CodingMarkus

lib/psst/basic.inc.sh

@@ -23,6 +23,9 @@ fi
 # shellcheck source=basic/chkcmd.inc.sh
 . "$INCLUDE_PSST/basic/chkcmd.inc.sh"
 
+# shellcheck source=basic/esc.inc.sh
+. "$INCLUDE_PSST/basic/esc.inc.sh"
+
 # shellcheck source=basic/conv.inc.sh
 . "$INCLUDE_PSST/basic/conv.inc.sh"
 

lib/psst/basic/esc.inc.sh

@@ -0,0 +1,44 @@
+#!/usr/bin/env sh
+
+# Double include protection
+case "$INCLUDE_SEEN_PSST" in
+	*_esc.inc.sh_*)
+		return
+		;;
+esac
+INCLUDE_SEEN_PSST="$INCLUDE_SEEN_PSST _esc.inc.sh_"
+
+
+# shellcheck source=assert.inc.sh
+. "$INCLUDE_PSST/basic/assert.inc.sh"
+
+
+##
+# SUBPROCESS
+#	esc_for_sq_psst <value>
+#
+# SUMMARY
+#	Escapes `value` so it can be safely used within single quotes. This
+#	means it only escapes single quotes themselves as all other characters,
+#	including backshlash, are safe to be used within single quotes. Basically
+#	`abc'def'`` becomes `abc'\''def`.
+#
+#
+# PARAMETERS
+#	value: Value to be escaped for usage within single quotes.
+#
+# OUTPUT
+#	stdout: The escaped value.
+#
+# SAMPLE
+#	safeValue=$( esc_for_sq_psst "$value" )
+#
+esc_for_sq_psst()
+(
+	value=$1
+
+	func="esc_for_sq_psst"
+	assert_argc_psst "$func" 1 $#
+
+	printf "%s" "$value" |  sed "s/'/'\\\''/g"
+)

test/basic/bin/test_esc.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env sh
+
+# Exit at once if a command fails and the error isn't caught
+set -e
+
+if [ -z "$INCLUDE_PSST" ]
+then
+	cmdBase=$( dirname "$0" )
+	INCLUDE_PSST="$cmdBase/../../../lib/psst"
+fi
+
+# shellcheck source=../../../lib/psst/basic.inc.sh
+. "$INCLUDE_PSST/basic.inc.sh"
+
+# =============================================================================
+# esc_for_sq
+
+# Must accept exactly one argument
+set +e
+( esc_for_sq_psst 2>/dev/null )
+[ $? = 127 ] || test_fail_psst $LINENO
+
+( esc_for_sq_psst 1 2  2>/dev/null )
+[ $? = 127 ] || test_fail_psst $LINENO
+set -e
+
+
+# Test the encoding
+[ "$( esc_for_sq_psst "" )" = ""  ] || test_fail_psst $LINENO
+[ "$( esc_for_sq_psst "abc" )" = "abc"  ] || test_fail_psst $LINENO
+[ "$( esc_for_sq_psst "ab'cd" )" = "ab'\\''cd"  ] || test_fail_psst $LINENO
+[ "$( esc_for_sq_psst "'a'b" )" = "'\\''a'\\''b"  ] || test_fail_psst $LINENO

test/basic/bin/test_ifs.sh

@@ -31,7 +31,6 @@ set +e
 set -e
 
 
-
 # Test push, pop
 oldIFS="$IFS"