CleanPath

What Is It?

For UNIX bash/sh (.profile, .bashrc)

I use multiple UNIX systems, but how does one set PATH, LD_LIBRARY_PATH, CLASSPATH, and PERL5LIB in .profile or .bashrc, keep it clean and free of duplicaes?

I want a common .profile across systems. However, not all systems have the same things installed. I inherit some stuff from the system itself, so I want to keep whatever that is.

Code Home

Primary Development: https://gitlab.home.vollink.com/external/cleanpath
Backup Location:     https://github.com/gavollink/cleanpath

Most Common Way

Here is the most common way to deal with PATH...

    PATH="$HOME/bin:$HOME/sbin:$PATH:/usr/local/bin"

If this system doesn't have $HOME/sbin, there's a path-hit fail every time a command is typed.

More Careful Way

    if [ -d $HOME/bin ]; then
        PATH=$HOME/bin:$PATH
    fi
    if [ -d $HOME/sbin ]; then
        PATH=$HOME/sbin:$PATH
    fi
    if [ -d /usr/local/bin ]; then
        PATH=$PATH:/usr/local/bin
    fi
    # In reality, this would go on for many, MANY more lines
    echo $PATH
    /home/you/bin:/usr/bin:/usr/sbin:/usr/local/bin

If for some reason my profile ran twice, then my PATH would mostly duplicate.

    echo $PATH
    /home/you/bin:/home/you/bin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/bin

This project but pure shell

Then, I started doing what this project does with shell commands. That logic loop is a sight to see. Notably, that can't currently deal with a directory name with a space in it, where cleanpath can.

Using CleanPath instead

Now my .profile looks like this...

    export PATH     # cleanpath cannot read what is not exported
    PATH=`cleanpath -Pb -- "${HOME:-x}/bin" "${HOME:-x}/sbin"`
    PATH=`cleanpath -P -- "/usr/local/bin"`

In reality, each line is longer, but there are no more individual lines to deal with PATH. PATH is likely already exported, but this is illustrative of any ENVNAME requested.

    echo $PATH
    /home/you/bin:/usr/bin:/usr/sbin:/usr/local/bin

• cleanpath -P will check each token in the PATH environment variable to verify it actually exists on the system.
• cleanpath -b puts the command line parameters before the PATH environment variable in the output.

Build (part 1)

Should work on any UNIX, though MacOS and Linux have been tested (check bottom of this README for more).

./configure

NOTE: The configure script is not GNU-autoconf. There are very few things this needs that aren't extremely standard across UNIX, so the ./configure is hand-written. configure outputs to configure.h and configure.mk

On macOS only...

Compiling on any macOS since Yosemite (10.10), make will automatically build a Universal arm64 & x86_64 binary.

Older than that, and it will just do the compile with no special targetting, like it does for any other Linux.

IF your mac is set up so that you MUST do local codesign before you can run self-compiled command line tools, then edit the 'configure.mk' file that the ./configure command produced. SIGNID= and CHAIN= can be set to get the Makefile to initiate that as part of the build.

Build (part 2)

make

This should build without warnings.

Install

There's only the one executable, copy it where you want?

BUT, uh, configure.mk CAN be edited to put in values for prefix and bindir, and if those are set then make install will do that one thing.

Non-obvious features

• cleanpath always removes dupliates from the combined output.
• cleanpath always removes dupliate delimiters from the output.
• cleanpath removes delimiters from the beginning and end of the output.

Using With Other Environment Variables

    LD_LIBRARY_PATH=`cleanpath -Pb LD_LIBRARY_PATH -- "$HOME/lib"`
    export LD_LIBRARY_PATH
    LD_LIBRARY_PATH=`cleanpath -P LD_LIBRARY_PATH -- "/usr/local/lib"`
    export LD_LIBRARY_PATH

Non environment lists

This illustrates using a different separator and not pulling an environment variable.

    $ cleanpath -XF, -- abcd efgh ijkl efgh mnop abcd qrst
    abcd,efgh,ijkl,mnop,qrst

Other examples

This is exactly equivalent to above, mixing delimited ADDENV and non-delimited, separate ADDENV as above.

    $ cleanpath -XF, -- abcd,efgh ijkl,efgh,mnop abcd qrst
    abcd,efgh,ijkl,mnop,qrst

Removing extra delimiters, as above, default delimiter.

    $ cleanpath -X ::::abcd: :efgh: :ijkl::efgh mnop:abcd: :qrst:::
    abcd:efgh:ijkl:mnop:qrst

Space as delimiter

    $ cleanpath -XF' ' "   abcd efgh ijkl efgh  " mnop abcd qrst
    abcd efgh ijkl mnop qrst

Options

As shown in the examples above, short options can be bundled -PbF-

--before
-b
    Put ENVADD before the contents of ENVNAME in final output.  Useless
    if --noenv is also used (will warn)
--exists
-e
    Verify that each --delimiter separated token exists.
--checkpaths
-P
    Verify that each --delimiter separated token is a valid directory.
--checkfiles
-f
    Verify that each --delimiter separated token is a valid file.
--delimiter :
-F:
    Single character delimiter for tokens both for output and inputs
    Defaults to colon (:)
--env
    A very explicit way to set the ENVNAME
--noenv
-X
    Do not pull tokens of an environment variable.
    Will warn if --before is specified.

ENVNAME
    Name of environment variable to pull in

--
    Stops looking for options, past this everything is seen as ENVADD
    Very necessary if an ENVADD starts with a '-'.

ENVADD
    Additional data to evaluate and add to output.
    If delimited in a single argument, the delimiter must match --delimiter

--debug
    Prints what it is doing as it happens, good for viewing if the output
    is not what was expected.
--help
    Not exactly the same as this, but has the same info.
--license
    Print the LICENSE.
--vdebug
    Super verbose and only useful for debugging
    changes to this program itself.  Only available if compiled in.

Cautions

• Use export before calling cleanpath, or cleanpath cannot read the environment variable.
• Cleanpath will preserve anything it can see that is not the delimiter:
  • cleanpath -X -- 'abcd' ' abcd' will output abcd: abcd
  • cleanpath -X -- abcd: abcd will output abcd (without quoting, it won't see the space)

TODO

I think the string-hanlding should be replaced with something more standard than the home-grown thing I'm using.

I'm thinking about an elegant way to deal with LD_FLAGS settings... where ' -L' precedes the folder to verify. Or CC_FLAGS where a ' -I' precedes a directory. There are a few places in my workflow where this would come in handy.

I haven't used csh since the 90s, but it is possible that for this to be useful under csh, some big adjustements might need to be made. If someone asks, I can probably make that happen.

Far off, I might consider auto-adjusting options based on the environment variable requested. For example cleanpath CLASSPATH -- ... could invoke different options to the defaults (-e) or (-Pf).

Reach out with requests.

Deliberately NOT Done

Some options do not have short alternatives. I set short options for everything that might be required in scripted use. Not for --env because ENVNAME defaults to the first bareword.

There are MANY features I could add, but this does what I need it to do in just less that 1400 lines of C.

Compile on UNIX

I am curious to know if anybody compiles this on another UNIX or a CPU other than x86, M1 (arm64) or one of the Raspberry Pis (armhf, armv7l, aarch64). Also, this is a low traffic project, I can probably help if you have issues.

firstname @ lastname . com