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I was trying to run a linux binary from this site:

specifically, the "compute_descriptors.ln"

However, the terminal only responded with command not found. The extension also looks very uncommon.

I am running Ubuntu 12.10.

share|improve this question
what command did you type? could you copy/paste the exact command and the exact repsonse? – Nanne Dec 12 '12 at 10:50
I downloaded the .gz file, extract it. then type "compute_descriptors.ln" in a terminal as indicated in the webpage mentioned. – nschong Dec 12 '12 at 10:53
I did change my path correctly – nschong Dec 12 '12 at 10:54
Sorry, just noticed typo in my question. the responds was "command not found" – nschong Dec 12 '12 at 10:56
up vote 1 down vote accepted

You probably typed

$ compute_descriptors.ln

but you need to do

$ ./compute_descriptors.ln

(notice the leading ./, that is also mentioned on the site you linked)
The command isn't known "globally" (in your path) so you must specify that the command is in fact in this directory.

You could also need to do a chmod +x, but i'd just try the ./ prepending first.

share|improve this answer
hi, thanks. actually, I made both mistakes. Just another questions: how do we add a folder to the "globally" known path. I assume that it is similar to the PATH environment variable in Windows? – nschong Dec 12 '12 at 11:34
You can set your path environment like you can read here: . – Nanne Dec 12 '12 at 12:24

I think you missed some steps (chmod +x maybe?). Works for me:

$ wget[...]/compute_descriptors.ln.gz                
2012-12-12 11:55:36 (1.55 MB/s) - `compute_descriptors.ln.gz' saved [3222607/3222607]                                            

$ gunzip compute_descriptors.ln.gz                                                                             
$ chmod +x compute_descriptors.ln 
$ ./compute_descriptors.ln 
Interest point descriptors implemented by                                                      
at INRIA Rhone-Alpes.[ref.]                                                      
share|improve this answer
oh thanks a lot. – nschong Dec 12 '12 at 11:01
just another questions, how did you notice it? I'm new to linux, – nschong Dec 12 '12 at 11:02
@soon This is basic file system permission and Bash. You would have run into the same with a basic script and trying to execute it. – gertvdijk Dec 12 '12 at 11:30
i see, thanks a lot for the tips – nschong Dec 12 '12 at 11:36

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