From the examples I expect this to work:

<% if [ $TEST ]; then %>
This should be printed when TEST is not empty.
<% fi %>

But it doesn't. Am I doing something wrong?

While it should be possible to implement the logic for include-once with the current functionality,
I'm wondering if you have thought of having that functionality built-in and if you'd accept a PR.

Thanks for creating esh btw ❗

Hi and thank you for this project that I've been using a bit recently !

Does it support loops ?

Thanks in advance

Firstly, thanks for sharing this tool, I'm use ESH to generate SQL scripts from a template and it just works great :)

This is the shell script I'm using:

#!/bin/sh

ESH_VERSION=0.1.1
ESH_FILE_NAME=esh-${ESH_VERSION}
ESH_DOWNLOAD_FILE_NAME=${ESH_FILE_NAME}.tar.gz
ESH_DOWNLOAD_BASE_DIR=/tmp
ESH_DOWNLOAD_DIR=/tmp/${ESH_FILE_NAME}
ESH_DOWNLOAD_PATH=${ESH_DOWNLOAD_BASE_DIR}/${ESH_DOWNLOAD_FILE_NAME}
ESH_BIN=${ESH_DOWNLOAD_BASE_DIR}/${ESH_FILE_NAME}/esh

usage () { echo "Script usage: $(basename $0) -p prefix -c collection_name"; }

while getopts ':p:c:h' OPTION; do
  case "$OPTION" in
    p) PREFIX="$OPTARG";;
    c) COLLECTION="$OPTARG";;
    h) usage; >&2 exit 1;;
    :) echo "Invalid option: $OPTARG requires an argument" 1>&2;;
    ?) usage; >&2 exit 1;;
  esac
done
shift "$(($OPTIND -1))"

# Download ESH if it wasn't downloaded before
if [ ! -d "$ESH_DOWNLOAD_DIR" ]; then
  wget https://github.com/jirutka/esh/archive/v${ESH_VERSION}/${ESH_DOWNLOAD_FILE_NAME} -O ${ESH_DOWNLOAD_PATH}
  tar -xzf ${ESH_DOWNLOAD_PATH} -C ${ESH_DOWNLOAD_BASE_DIR}
fi

printf "/*\n"
printf "+------------------------------------------+\n"
printf "            Scripts start here\n"
printf "+------------------------------------------+\n"
printf "*/\n"
printf "\n"

${ESH_BIN} template.sql PREFIX=${PREFIX} COLLECTION=${COLLECTION}
printf "\n"

printf "\n"
printf "\n"

printf "/*\n"
printf "+------------------------------------------+\n"
printf "             Scripts end here\n"
printf "+------------------------------------------+\n"
printf "*/\n\n"

Probably not the best script, but I have to acknowledge the fact that I'm not very good at shell/bash scripting 😅

Usage example: ./script.sh -p zz -c repliesworks just fine-

Now let's say I want to support an option -f whose argument is a set of table fields in the DDL script, for example: ./script.sh -p zz -c replies -f "my_field varchar(500) DEFAULT NULL"

It would fail with: esh: illegal argument: varchar(500)

Is there a way to somehow escape a variable's value? If not, IMHO it would be a nice feature :)

Cheers.

Hello. I try to use esh, but I need to create more comprehensive solution.

How to correct use for with if in template?

For example:

<% for application in ${applications} ; do -%>
        <% if "${application}" == "root" ; then -%>
                <% contextPath="/" -%>
        <% else -%>
                <% contextPath="/$application" -%>
        <% fi -%>

        <Context path="<%= $contextPath %>"  docBase="<%= $application %>.war"/>
<% done -%>

applications="root demo app"

but with this template I get next error:

test.xml:3: root: not found
test.xml:3: demo: not found
test.xml:3: app: not found

esh 0.3.1

nginx.tpl.esh

access_log <%= ${HOME}/nginx_access.log %> main;
    error_log <%= ${HOME}/error.lg %>;

    root <%= ${HOME}/APP_NAME %>; 

    <% if  [ -z "$location" ] || [ "${location}" == "/" ] && [ -n "$backend_url" ];then %>
    location / {
      proxy_pass <%= $backend_url %>;
      proxy_set_header Host $host;
    }
    <% fi %>

The same process that declared a variable will also report an error!

Hi!
First of all, kudos for this great little template engine! The attention to portability and correctness is really appreciated. 👏

I stumbled upon a little issue today as I was using the -o option: I realized that esh does not honor the umask value of its parent process and always produces files with the UNIX mode u+rw (0600) as the file is created by mktemp and not by esh itself:

This behavior can cause bugs in situations where the output file mode is expected to be something like rw-r--r-- (i.e. with the common and default 0022 umask value).
I think that replacing the mv command with something like cat "$tmpfile" > "$OUTPUT" should fix this.

On another note (not related to the issue above but I've realized this when reading the code), I think that the following line:

would be safer with the quotation marks (the single and double quotes) placed the other way around (and also because the $tmpfile variable seems to be always set on the occasions where the trap command would be triggered).

In a quite twisted scenario (i.e. where an adversary is able to create arbitrary directories in the filesystem and controlling the TMPDIR environment variable exposed to esh using the -o option) the trap command would then be vulnerable to a shell injection attack.

If the variable is not assigned, it should be empty value "", instead of error message "unbound variable"!

Current state: opened PR gentoo/gentoo#6222

First of all great job
I have always been looking for a template engine that works only with shell binaries.
The advantage for me is I don't need to install any annoying dependencies like with other template engines for example on python.

But I have a problem. The new lines are not present on the output if the preview line is a esh tag.
I am working with openwrt and I do have a lot off image. So that I do not have duplicated configuration files.
I sqashed them in one file as an template for esh to generate the different uci image configuration out of this file.
It works as expected, with a small bug I think.

The new line --><--- NEWLINE MISSING IN OUTPUT (see: Example code) is not present on the output. And if i remove the - in the if statement the line above <% fi %>. I get two new lines! So I do not know what is the problem. Is this maybe a bug?

Example code:

config interface 'lan'
<% if [ "$common_customer" = "abc" ]; then -%>
	option proto 'none'
<% else -%>
	option proto 'static'
	option netmask '255.255.255.0'
<% fi -%>
	option ifname 'eth1.1'
	option force_link '1'
<% if [ "$common_customer" = "123" ]; then -%>
	option ipaddr '192.168.0.1'
<% elif [ "$common_customer" = "xyc" ]; then -%>
	option ipaddr '192.168.0.254'
<% elif [ "$common_customer" = "abc" ]; then -%>
<% else -%>
	option ipaddr '192.168.0.50'
<% fi -%>
--><--- NEWLINE MISSING IN OUTPUT
config interface 'wan'
	option ifname 'eth0'
<% if [ "$network_wan_auto" != "yes" ]; then -%>
	option auto '0'
<% fi -%>
<% if [ "$network_wan_metric" != "default" ]; then -%>
	option metric '<%= $network_wan_metric %>'
<% else -%>
<% if [ "$common_customer" != "123" ]; then -%>
	option metric '100'
<% fi -%>
<% fi -%>
	option proto 'dhcp'

Hello,
Please note that I create this project for Erlang.mk plugin https://github.com/crownedgrouse/esh.mk using your project. Same LICENCE.
Great project ! Thanks

Current state: Opened request #1514934