Imported from ../bash-2.04.tar.gz.

examples/scripts/line-input.bash

@@ -0,0 +1,185 @@
+#! /bin/bash
+#
+#From: kaz@cafe.net (Kaz Kylheku)
+#Newsgroups: comp.unix.shell
+#Subject: Funky little bash script
+#Message-ID: <6mspb9$ft2@espresso.cafe.net>
+#Date: Thu, 25 Jun 1998 06:11:39 GMT
+
+#Here is something I wrote a few years ago when I was bored one day.
+#Warning: this contains control characters.
+
+# Line input routine for GNU Bourne-Again Shell
+# plus terminal-control primitives.
+#
+# by Kaz Kylheku
+# June 1996, Vancouver, Canada
+
+
+#
+# Function to disable canonical input processing.
+# Terminal modes are saved into variable "savetty"
+#
+#
+
+function raw
+{
+	savetty=$(stty -g)
+	stty -icanon -isig -echo -echok -echonl inlcr
+}
+
+#
+# Function to restore terminal settings from savetty variable
+#
+
+function restore
+{
+	stty $savetty
+}
+
+#
+# Set terminal MIN and TIME values.
+# If the input argument is a zero, set up terminal to wait for
+# a keystroke indefinitely. If the argument is non-zero, set up
+# an absolute timeout of that many tenths of a second. The inter-keystroke
+# timer facility of the terminal driver is not exploited.
+#
+
+function settimeout
+# $1 = tenths of a second
+{
+	if [ "$1" = "0" ] ; then
+		min=1
+		timeout=0
+	else
+		min=0
+		timeout="$1"
+	fi
+
+	stty min $min time $timeout
+
+	unset min timeout
+}
+
+#
+# Input a single key using 'dd' and echo it to standard output.
+# Launching an external program to get a single keystroke is a bit
+# of a pig, but it's the best you can do! Maybe we could convince the
+# GNU guys to make 'dd' a bash builtin.
+#
+
+function getkey
+{
+	eval $1="\"\$(dd bs=1 count=1 2> /dev/null)\""
+}
+
+#
+# Input a line of text gracefully.
+# The first argument is the name of a variable where the input line is
+# to be stored. If this variable is not empty, its contents are printed
+# and treated as though the user had entered them.
+# The second argument gives the maximum length of the input line; if it
+# is zero, the input is unlimited (bad idea).
+# ^W is used to delete words
+# ^R redraws the line at any time by backspacing over it and reprinting it
+# ^U backspaces to the beginning
+# ^H or ^? (backspace or del) delete a single character
+# ^M (enter) terminates the input
+# all other control keys are ignored and cause a beep when pressed
+# 
+#
+
+
+function getline
+{
+	settimeout 0			# No keystroke timeout.
+	save_IFS="$IFS"			# Save word delimiter and set it to
+	IFS=""				# to null so ${#line} works correctly.
+	eval line=\${$1}		# Fetch line contents
+	echo -n "$line"			# and print the existing line.
+	while [ 1 ] ; do
+		getkey key		# fetch a single keystroke
+		case "$key" in
+		 |  )				# BS or DEL
+			if [ ${#line} != 0 ] ; then	# if line not empty
+				echo -n " "		# print destructive BS
+				line="${line%%?}"	# chop last character
+			else				# else if line empty
+				echo -n 		# beep the terminal
+			fi
+			;;
+		 )					# kill to line beg
+			while [ ${#line} != 0 ] ; do	# while line not empty
+				echo -n " "		# print BS, space, BS
+				line="${line%?}"	# shorten line by 1
+			done
+			;;
+		 )					# redraw line
+			linesave="$line"		# save the contents
+			while [ ${#line} != 0 ] ; do	# kill to line beg
+				echo -n " "
+				line="${line%?}"
+			done
+			echo -n "$linesave"		# reprint, restore
+			line="$linesave"
+			unset linesave			# forget temp var
+			;;
+		 )
+			while [ "${line% }" != "$line" -a ${#line} != 0 ] ; do
+				echo -n " "
+				line="${line%?}"
+			done
+			while [ "${line% }" = "$line" -a ${#line} != 0 ] ; do
+				echo -n " "
+				line="${line%?}"
+			done
+			;;
+		 | 
 |  |  |  |  |  |  |  |  |  | 
 )
+			echo -n 	# ignore various control characters
+			;;		# with an annoying beep
+		 |  |  |  |  |  |  |  |  |  |  |  |  )
+			echo -n 
+			;;
+		'	' |  |  |  |  |  )
+			echo -n 
+			;;
+		'' )			# Break out of loop on carriage return.
+			echo		# Send a newline to the terminal.
+			break		# (Also triggered by NUL char!).
+			;;
+		* )		# Append character to the end of the line.
+				# If length is restricted, and the line is too
+				# long, then beep...
+
+			if [ "$2" != 0 -a $(( ${#line} >= $2 )) = 1 ] ; then
+				echo -n 
+			else				# Otherwise add
+				line="$line$key"	# the character.
+				echo -n "$key"		# And echo it.
+			fi
+			;;
+		esac
+	done
+	eval $1=\"\$line\"
+	IFS="$save_IFS"
+	unset line save_IFS
+}
+
+# uncomment the lines below to create a standalone test program
+#
+echo "Line input demo for the GNU Bourne-Again Shell."
+echo "Hacked by Kaz Kylheku"
+echo
+echo "Use ^H/Backspace/Del to erase, ^W to kill words, ^U to kill the"
+echo "whole line of input, ^R to redraw the line."
+echo "Pass an argument to this program to prime the buffer contents"
+raw
+echo -n "go: "
+if [ ${#1} != 0 ] ; then
+	LINE=$1
+fi
+getline LINE 50
+restore
+
+echo "<$LINE>"
+