msys path conversion (or cygpath for msys?)

path portability mingw32 msys cygpath
Pavel P picture Pavel P · Aug 18, 2012 · Viewed 23.5k times · Source

I need to pass /DEF:c:\filepath\myLib.def" command line option from a bash script to MS compiler/linker. The path is generated as part of build process by a bash script. Basically, the argument that my script passes is:

-DEF:/c/filepath/myLib.def

MSYS path conversion can't handle it properly because it doesn't understand /DEF: part. It works if I do 

-DEF=/c/filepath/myLib.def

but then ms tools don't understand this parameter. In short, what's the proper way to write that parameter in MSYS bash so that it converts it to proper argument?

On cygwin I could use cygpath, but there is no equivalent, because somebody from msys thinks that it's not needed (even if there are scripts for cygwin that uses cygpath).

Answer

Pavel P picture Pavel P · Aug 21, 2012

Update (Aug-2016):

This question is no longer relevant, as msys2 now comes with cygpath in its installation.

...

I'll summarize my research here.

The cygpath equivalent in MSYS is to use this command:

{ cd /c/some/path && pwd -W; } | sed 's|/|\\|g'

The problem with this approach is that it requires existing path, e.g. the c:\some\path has to be an existing directory; however, real cygpath supports paths that do not exist.

So, if you need to get path to a directory that doesn't exist, then you can fallback to sed conversion of the path:

{ cd 2>/dev/null /c/some/path && pwd -W ||
  echo /c/some/path | sed 's|^/\([a-z,A-Z]\)/|\1:/|'; } | sed 's|/|\\|g'

The mouthful of slashes is there to satisfy quoting rules of sed. So, if c:\some\path doesn't exist on your PC, it will try to convert forward to back slashes and replace /c/ with c:\ (or any other drive letter). The only drawback for this is that it won't work correctly non-existing paths that contain a mounted component, such as /bin/does-not-exist or /usr/bin/does-not-exist.

One more approach is to use cygpath from cygwin in MSYS. It seems that cygwin sets global environment variable CYGPATH, that is, you can use it from regular cmd.exe:

%CYGPATH% -w /c/some/path
C:\some\path

or from MSYS:

$CYGPATH -w /c/some/path
C:\some\path

as long as you set to point /c to /cygdrive/c in cygwin. But this approach will print you /usr located in cygwin installation, not in MSYS.

In short, I think msys should really include real cygpath in the default set of tools just for some cases that aren't handled automatically by msys command line argument conversion logic

Related questions

How can I safely create a nested directory?

What is the most elegant way to check if the directory a file is going to be written to exists, and if not, create the directory using Python? Here is what I tried: import os file_path = "/my/directory/filename.…

Read More
How to permanently set $PATH on Linux/Unix?

I'm trying to add a directory to my path so it will always be in my Linux path. I've tried: export PATH=$PATH:/path/to/dir This works, however each time I exit the terminal and start a new terminal …

Read More
Adding a directory to the PATH environment variable in Windows

I am trying to add C:\xampp\php to my system PATH environment variable in Windows. I have already added it using the Environment Variables dialog box. But when I type into my console: C:\>path it doesn't show …

Read More