guangie88 / envja

CLI to perform env var interpolation in a Jinja2-lite syntax

Envja

Performs environment variable interpolation in a Jinja2-lite syntax.

Contains both the CLI and the library component.

How to install CLI

Via cargo

cargo install envja

Simple Examples

Direct

envja direct '{% if VAL %}VAL={{VAL}}{% endif %}'

Should return empty string because VAL env var is missing.

VAL=hello envja direct '{% if VAL %}VAL={{VAL}}{% endif %}'

Should return VAL=hello.

Direct via STDIN

With similar set-up like in Direct:

echo -n '{% if VAL %}VAL={{VAL}}{% endif %}' | envja direct

echo -n '{% if VAL %}VAL={{VAL}}{% endif %}' | VAL=hello envja direct

Via file

With similar set-up like in Direct:

echo -n '{% if VAL %}VAL={{VAL}}{% endif %}' > test.tmpl
envja file test.tmpl
rm test.tmpl

echo -n '{% if VAL %}VAL={{VAL}}{% endif %}' > test.tmpl
VAL=hello envja file test.tmpl
rm test.tmpl

Complex Example

echo '{% if LINUX_HEADER %}#include <{{LINUX_HEADER}}>{% endif %}
int main() {
    return {{ RET }};
}' > test.tmpl
LINUX_HEADER=unistd.h RET=123 envja file test.tmpl
rm test.tmpl

Should print:

#include <unistd.h>
int main() {
    return 123;
}

Syntax Acceptance

If-statement

{% if ENV %}ENV value is {{ ENV }}{% endif %}

Expression

{{ ENV }}

Comments

{# comments #}

Regular text

Regular text

envja's Issues

Allow `elif` and `else` for flexibility

Allow processing of list?

Should be possible to inject JSON value as string into any env var, then when used in for loop context, the var can be interpreted as a list value.