betweenGo

Running Java scripts in Cygwin bash scripts becomes a little tricky because you want to treat most paths in Cygwin as normal UNIX paths but Java expects DOS paths.  Therefore to get around this you can use the mixed option for cygpath.

For example:

if [ -e /usr/bin/cygpath ] || [ -e /bin/cygpath ]
then
  export FOO=`cygpath --mixed "e:\work\betweengo/target/foo"`
else
  export FOO="e:\work\betweengo/target/foo"
fi

The result on Cygwin is that FOO will be set to “e:/work/betweengo/target/foo” which will work both in DOS and UNIX.

In a previous post, Shell Scripts with Windows LF’s Fail in Latest Cygwin, I wrote about how to use Perforce to check out all files in UNIX format. However if you use Eclipse then this solution will not work because Eclipse always inserts Windows LF’s in any line you insert into a file leading to a mess with files that have both UNIX and Windows LF’s.

However if you happen to use Maven to generate / copy your shell scripts to their target directories you can take advantage of the lineEnding property in the Assembly Director. If you specify the lineEnding property to be “unix” then the outputted shell scripts will be in UNIX format. For example:

<file>
  <source>src/main/scripts/foo.sh</source>
  <outputDirectory>bin</outputDirectory>
  <lineEnding>unix</lineEnding>
</file>

I am not sure when this happened but now in Cygwin shell scripts with Windows LF’s (the infamous control M’s) fail, i.e. Cygwin fails to run them because it will complain about the ‘\r’ character.

The simple way to fix this is to change your scripts to use UNIX LF’s by calling dos2unix or “conv -U”.

If you are using Perforce on Windows and seeing this problem then you can change your client to use “share” for the LineEnd option. Since Perforce stores all its text files in UNIX format on the server then it will write them out locally on your Windows machine in UNIX format. See the Perforce Knowledge Base article, CR/LF Issues and Text Line-endings. Fortunately Windows batch scripts with UNIX LF’s still run properly.

Note that when you make this change from the “local” LineEnd option then text files you already checked out will have the Windows LF’s. You will need to do a p4 sync -f on the files you want updated to have UNIX LF’s. Also when do you a p4 diff on your opened text files it will look like the whole file has changed. Again this is because of line feed issues. Doing a dos2unix on those opened text files will solve the problem.

Whenever I start my bash shell I get this annoying message.

Your group is currently “mkgroup”.  This indicates that
the /etc/group (and possibly /etc/passwd) files should be rebuilt.
See the man pages for mkpasswd and mkgroup then, for example, run
mkpasswd -l [-d] > /etc/passwd
mkgroup  -l [-d] > /etc/group
Note that the -d switch is necessary for domain users.

I tried doing what the documentation but I still kept getting that message.  I then tried one of the suggestions in the comments of this post, Cygwin users and groups « sinewalker.

$ mkpasswd -l -p /home/ -c > /etc/passwd

$ mkgroup -l -c> /etc/group

I then got this message.

Copying skeleton files.
These files are for the user to personalise
their cygwin experience.

These will never be overwritten.

`./.bashrc’ -> `/home/fkim//.bashrc’
`./.bash_profile’ -> `/home/fkim//.bash_profile’
`./.inputrc’ -> `/home/fkim//.inputrc’
Your group name is currently “mkgroup_l_d”. This indicates that not
all domain users and groups are listed in the /etc/passwd and
/etc/group files.
See the man pages for mkpasswd and mkgroup then, for example, run
mkpasswd -l -d > /etc/passwd
mkgroup  -l -d > /etc/group

This message is only displayed once (unless you recreate /etc/group)
and can be safely ignored.

I am not sure what it means but it was only displayed once.  Now that I am not seeing it anymore I’m happy.

To get Perforce to work with Cygwin is not too difficult. One just has to make an alias for p4 like this (thanks to this excellent Perforce FAQ).

if [ -e /bin/cygpath ]; then
  alias p4='p4 -d `cygpath -w $PWD`'
fi

This alias works all the time except I think when you are in a directory you accessed via a link.

Note you don’t need to go such lengths as described in this post.

As of bash 3.2.9-10, bash no longer executes DOS formatted scripts as detailed in this announcement. I understand the reasoning for this is that:

1. cygwin is supposed to mimic Linux, not Windows
2. it is faster to assume that the scripts are in UNIX format

To get around this restriction I did what was recommended in this bug report, i.e. I created a Windows user environment variable named “SHELLOPTS” with the value “igncr”.

After installing Cygwin when I tried to start the shell from a Windows command prompt by entering the “sh” command a window would pop up with this error.

The procedure entry point rl_getenv_hook could not be located in the dynamic link library cygreadline6.dll.

After seeing this error I would have to manually kill the sh process using the Windows Task Manager.

There was a thread about this on the Cygwin mailing list. I did what was suggested and discovered that bin/sh.exe and bin/bash.exe were exactly the same. Yet for some reason when I ran bash from the Windows command prompt I did not get this error.

I then tried rerunning the Cygwin installer. Even though nothing was installed that seemed to solve the problem, i.e. I was able to run sh from the Windows command prompt. This was possibly because the bash postinstall script was run correctly.

Update: After reboot I am experiencing the same problem again. Aargh!