change default behaviour if lesspipe.sh is named differently

README.md

@@ -114,7 +114,11 @@ the author by email.
 ```
  If `lesspipe.sh` is not in the UNIX search path or if the wrong `lesspipe.sh` is
  found in the search path, then the full path to `lesspipe.sh` should be given
- in the above commands.
+ in the above commands. The above commands work only in the described manner
+ if the file name is lesspipe.sh.
+
+ If it is installed under a different name then calling it without an argument
+ will work as a filter with LESSQUIET set and expecting input from STDIN.
 
  The command to set **LESSOPEN** can also be displayed by calling `lesspipe.sh`
  without arguments. This can even be used to set **LESSOPEN** directly:

lesspipe.1

@@ -53,8 +53,13 @@ This can even be used to set \fBLESSOPEN\fP directly:
 .I lesspipe.sh|source /dev/stdin
 (zsh)
 .RE
+The above commands work only in the described manner if the file name is
+\fBlesspipe.sh\fP.
+If it is installed under a different name then calling it without an argument
+will work as a filter with \fBLESSQUIET\fP set and expecting input from STDIN.
+.PP
 Having set the environment variable as described above, \fBless\fP
-will then display textual information for a wide range of file formats.
+:will then display textual information for a wide range of file formats.
 .PP
 The filter is normally not called if input is piped to less as in
 .RS

lesspipe.sh

@@ -829,7 +829,7 @@ if [[ $LESSOPEN == *\|-* && $1 == - ]]; then
 	nexttmp >/dev/null
 fi
 
-if [[ -z "$1" ]]; then
+if [[ -z "$1" && "$0" == */lesspipe.sh ]]; then
 	[[ "$0" == /* ]] || pat=$(pwd)/
 	if [[ "$SHELL" == *csh ]]; then
 		echo "setenv LESSOPEN \"|$pat$0 %s\""
@@ -843,5 +843,10 @@ else
 	elif has_cmd lessfilter; then
 		lessfilter "$1" && exit 0
 	fi
-	show "$@"
+	if [[ -z "$1" ]]; then
+		LESSQUIET=1
+		show -
+	else
+		show "$@"
+	fi
 fi