Breaking: Stdin, parameters and docs

Author: pedroamador

README.md

@@ -8,7 +8,7 @@ Its a part of the Docker Command series
 
 Execute the following within your repository folder:
 
-- Using Bash: `entrypoint.sh source.md > target.html` or `cat target.HTML | entrypoint.sh > target.html`
+- Using Bash: `entrypoint.sh source.md > target.html` or `cat target.HTML | entrypoint.sh - > target.html`
 - Using Docker: `docker run --rmi -v $(pwd):/workspace kairops/dc-md2html source.md > target.html`
 - Using docker-command-launcher: `kd md2html source.md > target.html`
 
@@ -20,4 +20,4 @@ This function uses the `markdown` package. You could install with:
 - Linux DEB package: `apt-get install markdown`
 - Linux RPM package:  `yum install epel-release` + `yum install discount` (`markdown` command)
 
-You can use either `cat source.md | kd md2html > target.html` or `kd md2html source.md > target.html` format
+You can use either `cat source.md | kd md2html - > target.html` or `kd md2html source.md > target.html` format. If you use `-` as parameter the standard input will be processed.

entrypoint.sh

@@ -1,24 +1,37 @@
 #!/bin/bash
 
+set -euo pipefail
+
+function echo_err () {
+    echo >&2 -e "$@"
+}
+
+# Parameter check
+if [ $# -eq 0 ]; then
+    echo_err ">>>>>> md2html: You should use [filename] as parameter or '-' to read from stdin."
+    exit 1
+fi
+
 # markdown command check
 markdownCMD="$(which markdown)"
 if [ "$markdownCMD" == "" ]; then
-    echo "Missing 'markdown' command. Abort"
+    echo ">>>>>> md2html: Missing 'markdown' command. Abort"
     exit 1
 fi
 
 # Generate HTML from Markdown file if we have it as parameter
-if [ "$1" != "" ]; then
+echo $1
+if [ "$1" != "-" ]; then
     if [ -f $1 ]; then
         $markdownCMD $1
         exit 0
     else
-        echo "File $1 does not exist. Abort"
+        echo_err ">>>>>> md2html: File $1 does not exist. Abort"
         exit 1
     fi
 fi
 
-# Generate HTML from standard input
-(while read -t 5 line; do
-    echo $line
+# Generate HTML from stdin
+(while IFS= read -r line; do
+    printf '%s\n' "$line"
 done)|$markdownCMD