Improved Docker-related documentation.

Also introduced new Docker image versioning.

docker/README.md

@@ -43,6 +43,9 @@ A container is created from the `matejak/argbash` image.
 * The `-e PROGRAM=argbash` option is redundant and it basically affirms the container to invoke `argbash`. If you specify `PROGRAM=argbash-init`, `argbash-init` will be invoked instead, default program is `argbash`.
 * The `-v ...:/work` mounts the current directory to the working directory of the container, which is `/work`.
 * The `"$@"` or `%*` propagates any arguments given to this one-liner script to the `argbash` invocation in the container.
+  Make sure that you use the `-o|--output` option - if you intend to use the Argbash output from stdout, the line endings will be of the DOS kind (i.e. `\r\n` instead of just `\n` - thanks to [Filip Filmar](https://github.com/filmil) who found this out).
+
+Note that as the container mounts the host directory, you may have issues with SELinux or similar measures enforcing proactive security.
 
 
 Example

docker/entrypoint.sh

@@ -3,4 +3,19 @@
 LAUNCH="argbash"
 test "$PROGRAM" = 'argbash-init' && LAUNCH="argbash-init" || true
 
+encountered_output_option=no
+for arg in "$@"; do
+	if printf "%s" "$arg" | grep -q -e '^\(-o\|--output\)\>'; then
+		encountered_output_option=yes
+		break
+	fi
+done
+
 "${LAUNCH}" "$@"
+
+if test "$encountered_output_option" != yes; then
+	echo '# It seems that you use the output to stdout.' >&2
+	echo '# Beware, docker is likely to change line endings to DOS line endings.' >&2
+	echo '# This will make the script not executable on Unixes, unless you convert \r\n to \n' >&2
+	echo '# Use the -o|--output option to save the output to a file.' >&2
+fi

docker/handle_image.sh

@@ -4,7 +4,7 @@ set -e
 
 version="$(cat ../src/version)"
 
-another_tag="matejak/argbash:$version"
+another_tag="matejak/argbash:$version-${pkgrel:-1}"
 another_tag_option=(-t "$another_tag")
 dest="$version.tar.gz"