Lax

An argument substitution utility intended to make working on projects with deeply nested directories a bit easier.

"Lax" stands for "Locate Arguments and Execute."

Basic Usage

Given a binary and an "@" pattern "@foo", Lax will will find the file "foo" and replace "@foo" with "foo"'s full path, then execute the binary with the new arguments

lax echo @foo -> echo ./foobar/foo

Multiple "@" patterns are possible:

lax stat @foo @bar @baz -> stat ./foobar/foo ./foobar/target/bar ./foobar/src/baz

Mixing and matching "@" patterns and normal arguments is also possible:

lax cat -n @foo bar @baz -> cat -n ./foobar/foo bar ./foobar/src/baz

Globbing

Globbing is fully supported via globset.

lax echo @*.rs -> echo ./some/directory/main.rs

** is also supported, but is treated specially. The portion of the pattern before the first /**/(note the surrounding slashes) is the search entry point. That is, given a pattern like @foo/**/bar, Lax will look in the directory ./foo for a file that matches bar. Any following ** are handled normally:

$ lax echo @foo/**/bar/**/baz
foo/bizz/bazz/bar/beez/baz

Will look in directory ./foo for a path that matches bar/**/baz. That is, any entity baz that is a descendent of directory bar.

Making use of the search entry point can speed up searches if you know which top-level subdirectory your query is in, but you don't want to cd into it for whatever reason. It can also be used to specify a path outside your directory.

Using in Git Repositories

You can search from the git root by using a %:

lax vim @%README.md

Selectors

If there are multiple files matching the given name, Lax will prompt you to choose. However, you can also specify which file you'd want ahead of time:

$ lax echo @*.rs^1 # Select the first match
a.rs
$ lax echo @*.rs^2 # Select the second match
b.rs
$ lax echo @*.rs^l # Select the last match. You can also use '-1'
d.rs
$ lax echo @*.rs^-2 # Select the second to last match
c.rs
$ lax echo @*.rs^1,3 # Select the first and third match
a.rs c.rs
$ lax echo @*.rs^a # Select all matches
a.rs b.rs c.rs d.rs
$ lax echo @*.rs^/[ab] # Select with regex
a.rs b.rs

Now you know the full syntax for "@" patterns:

@[%][SEARCH_ENTRY_POINT/**/]GLOB_PATTERN[^SELECTOR[,SELECTOR]...]

Where SEARCH_ENTRY_POINT is a directory, GLOB_PATTERN is a glob pattern, and SELECTOR is [-n..-1|1..n|'a'|'l'|/regex]

Miscellaneous Features

# Escape the initial '@' symbol
$ lax echo \\@
@
$ lax echo '\@'
@

# Only match *directories* by adding a forward slash
$ lax echo @foo/
./foo/

# You can also use command-line options to achieve a similar effect
$ lax -d echo @foo
./foo/

# Or only look for files
$ lax -f echo @foo
./tests/foobar/foo

# Or transform a file to its parent
$ lax -fD echo @foo
./tests/foobar

# We also have the ability to specify fallback binaries. This will use `cowsay`
# if it's installed, otherwise it will fallback to `echo`
$ lax 'cowsay|echo' hello
 _______
< hello >
 -------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

Primary Use Case

In your .bashrc, you can write alias vim="lax vim"

From now on, you can just write:

vim @foo -> vim ./foobar/foo

This makes working on projects with deep directories, like U-Boot and Yocto, easier. If the compiler complains about an error in my_stupid_little_c_file.c, you can:

vim @*stupid*file.c

Using With cd

You might try to use Lax to do things like:

lax cd @some_deep_nested_subdirectory

But you will quickly discover this does not work as intended, as cd is affecting the current directory of its environment, which belongs to a child process of the shell.

Instead, you can add this to your .bashrc:

cd(){
    local args;
    if ! args=$(lax -pd -- ${@}); then
        return 1
    fi
    command cd ${args}
}

The -p flag tells Lax to not execute anything, but simply transform arguments and print them to stdout. The -d flag tells it to only match with directories, as cd has no interest in files. You could also use the -D flag if you want to match files, but cd to their parent directory, instead.

Installing

cargo install --git https://github.com/Property404/lax

or for a more optimized build:

cargo install --git https://github.com/Property404/lax --profile lto

License

MIT or Apache-2.0