Bug #1580

ctools cannot read filename using "~" referring to home directory

Added by Mayer Michael about 7 years ago. Updated about 7 years ago.

Status:ClosedStart date:11/19/2015
Priority:LowDue date:
Assigned To:Knödlseder Jürgen% Done:

100%

Category:-
Target version:-
Duration:

Description

I am not sure if this is more a feature than a bug.
Running a ctool on my mac and trying to load a file on my Desktop in the following way results in an error:

$ ctselect
Input event list or observation definition file [events.fits] ~/Desktop/obs.xml 
*** ERROR in GXml::load(std::string&): Unable to open file "~/Desktop/obs.xml" 
*** ERROR encounterted in the execution of ctselect. Run aborted ...

The file is however present. The following call works:
$ ctselect 
Input event list or observation definition file [~/Desktop/obs.xml] /Users/mimayer/Desktop/obs.xml 

Tracing the problem, I wind up in gammalib::expand_env. The function does not interpret “~” in a string (e.g. as $HOME).


Recurrence

No recurrence.

History

#1 Updated by Knödlseder Jürgen about 7 years ago

Interesting, I thought that the decoding of the ~ symbol happens on the system level, but this seems not to be the case.

Note, however, that ~mike means /home/mike (or /Users/mike on Mac OS X).

I agree that both capabilities should be added to gammalib::expand_env.

#2 Updated by Mayer Michael about 7 years ago

I just verified this does not work on Scientific Linux, too.
I am not sure how the function gammailib::expand_env works exactly. Is it an effort for you to implement this?

#3 Updated by Knödlseder Jürgen about 7 years ago

I can look into that. Is it an urgent issue?

#4 Updated by Knödlseder Jürgen about 7 years ago

  • Assigned To set to Knödlseder Jürgen

#5 Updated by Mayer Michael about 7 years ago

This probably belongs to the gammalib project after all.

I can look into that. Is it an urgent issue?

Thanks. No, not urgent at all simple workaround is to specify absolut paths. I just noted it and wanted it to be documented that we do not forget.

#6 Updated by Knödlseder Jürgen about 7 years ago

  • Project changed from ctools to GammaLib

#7 Updated by Knödlseder Jürgen about 7 years ago

Here the logic how bash treats the tilde: http://www.gnu.org/software/bash/manual/html_node/Tilde-Expansion.html

See the following link to learn how to access a users home directory: http://stackoverflow.com/questions/2910377/get-home-directory-in-linux-c

#include <unistd.h>
#include <sys/types.h>
#include <pwd.h>

const char *homedir;

if ((homedir = getenv("HOME")) == NULL) {
    homedir = getpwuid(getuid())->pw_dir;
}
Use getpwnam to retrieve the pw structure for an arbitrary user: http://linux.die.net/man/3/getpwnam

#8 Updated by Knödlseder Jürgen about 7 years ago

  • Status changed from New to Closed
  • % Done changed from 0 to 100

I added the interpretation of ~, ~user, ~+ and ~- to the gammalib::expand_env() function.

Merged into devel.

Also available in: Atom PDF