From f3b2b40b91ae97a6ad166382c593497efbb458ea Mon Sep 17 00:00:00 2001
From: Tom Scavo <trscavo@internet2.edu>
Date: Sun, 28 May 2017 17:28:12 -0400
Subject: [PATCH] Accept input from stdin

---
 bin/run_xslt_scripts.sh | 85 +++++++++++++++++++++++------------------
 1 file changed, 47 insertions(+), 38 deletions(-)

diff --git a/bin/run_xslt_scripts.sh b/bin/run_xslt_scripts.sh
index bc6b39f..707db6b 100755
--- a/bin/run_xslt_scripts.sh
+++ b/bin/run_xslt_scripts.sh
@@ -30,13 +30,14 @@ display_help () {
 	The script depends on cached metadata. It will not fetch
 	a metadata file from the server.
 	
-	Usage: ${0##*/} [-hv] -u MD_LOCATION -d OUT_DIR "XSL_FILENAME [OUTPUT_FILENAME]" ...
+	Usage: ${0##*/} [-hv] -u MD_LOCATION -d OUT_DIR ["XSL_FILENAME [OUTPUT_FILENAME]" ...]
 	
 	The script takes an arbitrary sequence of compound command-line
 	arguments. The second sub-argument of each compound argument is
 	OPTIONAL. If no OUTPUT_FILENAME is given for a particular
 	XSL_FILENAME, the script computes an output filename as best
-	it can.
+	it can. If there are no command-line arguments, the script takes
+	its input from stdin.
 	
 	Options:
 	   -h      Display this help message
@@ -214,21 +215,26 @@ if [ ! -d "$out_dir" ]; then
 	exit 2
 fi
 
-# check command-line arguments
-shift $(( OPTIND - 1 ))
-if [ $# -eq 0 ]; then
-	echo "ERROR: $script_name: wrong number of arguments: $# (at least one required)" >&2
-	exit 2
-fi
-
 #######################################################################
 # Functions
 #######################################################################
 
 # process a compound command-line argument
-# present that argument to this function as a pair of arguments:
+#
+# present a pair of arguments to this function:
 #   XSL_FILENAME [OUTPUT_FILENAME]
-# if the latter is omitted, the function computes a suitable output filename
+# if the latter is omitted, the function computes an output 
+# filename according to the following algorithm:
+# 
+# if the XSL filename is of the form
+#   base_filename_csv.xsl
+# or
+#   base_filename_json.xsl
+# then construct the output filename with the indicated extension:
+#   base_filename.csv
+# or
+#   base_filename.json
+# otherwise the output filename is the XSL filename sans the .xsl extension
 process_arg () {
 
 	local xsl_file
@@ -254,7 +260,7 @@ process_arg () {
 	xsl_file="$LIB_DIR/$1"
 	if [ ! -f "$xsl_file" ]; then
 		echo "ERROR: $FUNCNAME: lib file does not exist: $xsl_file" >&2
-		exit 4
+		return 4
 	fi
     
     # capture array elements
@@ -266,15 +272,6 @@ process_arg () {
 	if [ -z "$output_filename" ]; then
 	
 		# compute the output filename
-		
-		# if the XSL filename is of the form
-		#   base_filename_csv.xsl
-		# or
-		#   base_filename_json.xsl
-		# then construct the output filename with the corresponding extension:
-		#   base_filename.csv
-		#   base_filename_.son
-		# otherwise the output filename is the XSL filename sans the .xsl extension
 		base_filename="${1%%.*}"
 		if [[ $base_filename =~ _(csv|json)$ ]]; then
 			output_filename=$( echo "$base_filename" | $_SED -e 's/^\(.*\)_\([^_]*\)$/\1.\2/' )
@@ -312,30 +309,42 @@ if [ $status_code -ne 0 ]; then
 	exit 2
 fi
 
-# specify input file
+# specify output file for SAML metadata
 xml_file="${tmp_dir}/saml-metadata.xml"
 
+# read the input arguments into a temporary file
+in_file="${tmp_dir}/tmp_file_in.txt"
+shift $(( OPTIND - 1 ))
+if [ "$#" -gt 0 ]; then
+	# read input from the command line
+	while (( "$#" )); do
+		# copy command-line arg into the temp file
+		echo "$1" >> "$in_file"
+		shift
+	done
+else
+	# read input from stdin
+	/bin/cat - > "$in_file"
+fi
+
 # declare arrays
-xsl_filenames=()
-xsl_files=()
-out_filenames=()
-out_files=()
-
-# iterate over the command-line arguments
-num_args=$#  # TODO: simplify this loop
-for (( i = 0; i < num_args; i++ )); do
-
-	# process the next command-line arg
-	# (do not quote the arg)
-	process_arg $1
+declare -a xsl_filenames
+declare -a xsl_files
+declare -a out_filenames
+declare -a out_files
+
+# iterate over the input arguments
+while read line; do
+
+	# process the next line
+	# (do not quote the line)
+	process_arg $line
 	status_code=$?
 	if [ $status_code -ne 0 ]; then
-		echo "ERROR: $script_name failed ($status_code) to process arg $1" >&2
+		echo "ERROR: $script_name failed ($status_code) to process data: $line" >&2
 		exit 2
 	fi
-	
-	shift 
-done
+done < "$in_file"
 
 #######################################################################
 # Main processing