Slow load time of bash in cygwin

bash debugging cygwin bash-completion
Forethinker picture Forethinker · Mar 20, 2013 · Viewed 11.1k times · Source

At the moment bash takes about 2 seconds to load. I have ran bash with -x flag and I am seeing the output and it seems as though PATH is being loaded many times in cygwin. The funny thing is I use the same file in linux environment, but it works fine, without the reload problem. Could the following cause the problem?

if [ `uname -o` = "Cygwin" ]; then
    ....
fi

Answer

me_and picture me_and · Mar 26, 2013

As you've noted in your answer, the problem is Cygwin's bash-completion package. The quick and easy fix is to disable bash-completion, and the correct way to do that is to run Cygwin's setup.exe (download it again if you need to) and select to uninstall that package.

The longer solution is to work through the files in /etc/bash_completion.d and disable the ones you don't need. On my system, the biggest culprits for slowing down Bash's load time (mailman, shadow, dsniff and e2fsprogs) all did exactly nothing, since the tools they were created to complete weren't installed.

If you rename a file in /etc/bash_completion.d to have a .bak extension, it'll stop that script being loaded. Having disabled all but a select 37 scripts on one of my systems in that manner, I've cut the average time for bash_completion to load by 95% (6.5 seconds to 0.3 seconds).

Related questions

How can I make Perl and Python print each line of the program being executed?

I know that bash -x script.sh will execute script printing each line before actual execution. How to make Perl and Python interpreters do the same?

Read More
bash: debug option and functions

If I run bash -x myscript.sh I'll get debugging output. But if I have a function in myscript.sh, the code in the function is immune to -x option. It writes to output only the name of the function. …

Read More
How to concatenate string variables in Bash

In PHP, strings are concatenated together as follows: $foo = "Hello"; $foo .= " World"; Here, $foo becomes "Hello World". How is this accomplished in Bash?

Read More