Bash – Why did BASH print “bash: cd: write error: Success”

bash

I noticed this several times today. If I type cd ../Directory to change to another directory, it prints "bash: cd: write error: Success". I can't determine what other previous commands might be related to this.

typeset -f prints nothing.
alias prints nothing.
type -a cd prints "cd is a shell builtin".
echo $CDPATH prints an empty line.
$BASH_VERSION prints "bash: 4.2.37(1)-release: command not found".
I only noticed this 2-3 times. The initial directory and target directory were identical in both situations. I changed directories in this manner many other times, but did not encounter the error always.

What could be causing this?

Best Answer

Maybe a bug?

This sounds like a potential bug. I found a similar report showing the same message. The bug bash: pwd builtin exits with write error: Success.

excerpt

This message will be displayed if ferror(stdout) returns non-zero. For some reason (probably the fflush() call immediately preceding the check), stdio is causing ferror() to return true without setting errno.

Does this happen twice in a row? The pwd builtin calls clearerr() after printing the error message, so even if the stdout error flag `sticks', that should clear it.

Can't update history?

The error makes me think that it was successful in changing directories, but wasn't able to write the command cd ../Directory to your $HOME/.bash_history. I'd confirm that this file is intact and is writable. Also confirm that your $HOME directory is writable and not full.

$ df -h $HOME
Filesystem                         Size  Used Avail Use% Mounted on
/dev/mapper/fedora_greeneggs-home  402G  157G  225G  42% /home

Related Solutions

Bash – Debugging hanging bash process

Try

strace -p 14229

I will print every syscall that the process invokes. Then you see what the process actually does.

http://try-linux.blogspot.de/2013/12/how-to-strace-process.html

Bash Scripting – Benefits of Writing Entire Script in Functions

I've started using this same style of bash programming after reading Kfir Lavi's blog post "Defensive Bash Programming". He gives quite a few good reasons, but personally I find these the most important:

procedures become descriptive: it's much easier to figure out what a particular part of code is supposed to do. Instead of wall of code, you see "Oh, the find_log_errors function reads that log file for errors ". Compare it with finding whole lot of awk/grep/sed lines that use god knows what type of regex in the middle of a lengthy script - you've no idea what's it doing there unless there's comments.
you can debug functions by enclosing into set -x and set +x. Once you know the rest of the code works alright , you can use this trick to focus on debugging only that specific function. Sure, you can enclose parts of script, but what if it's a lengthy portion ? It's easier to do something like this:
```
 set -x
 parse_process_list
 set +x
```
printing usage with cat <<- EOF . . . EOF. I've used it quite a few times to make my code much more professional. In addition, parse_args() with getopts function is quite convenient. Again, this helps with readability, instead of shoving everything into script as giant wall of text. It's also convenient to reuse these.

And obviously, this is much more readable for someone who knows C or Java, or Vala, but has limited bash experience. As far as efficiency goes, there's not a lot of what you can do - bash itself isn't the most efficient language and people prefer perl and python when it comes to speed and efficiency. However, you can nice a function:

nice -10 resource_hungry_function

Compared to calling nice on each and every line of code, this decreases whole lot of typing AND can be conveniently used when you want only a part of your script to run with lower priority.

Running functions in background, in my opinion, also helps when you want to have whole bunch of statements to run in background.

Some of the examples where I've used this style: