Unable to launch the requested CGI program: /www/cgi-bin/first.cgi: Text file busy

Question

I'm trying to make a very simple shell script to run as a CGI on a uhttpd server running on an OpenWRT install.

The file is called /www/cgi-bin/first.cgi and looks like...

#!/bin/sh
echo "Content-type: text/html"
echo ""
echo "<html><head><title>Bash as CGI"
echo "</title></head><body>"
echo "<h1>Hello world</h1>"
echo "Today is $(date)"
echo "</body></html>"

...and I did a

chmod +x first.cgi

on the file.

When I try to pull up...

http://192.168.15.1/cgi-bin/first.cgi

...the browser gets...

Unable to launch the requested CGI program:
/www/cgi-bin/first.cgi: Text file busy"

I can cat and vi the file from a shell prompt, so not sure how the file is busy or even how I would find out.

What am I doing wrong?

1. What does your apache log say? 2. Does it work if you go to the directory where the script lives and try to run it using `./first.cgi`? — Jenny D, Mar 31 '14 at 17:01

score 2 · Answer 1 · edited Mar 31 '14 at 18:52

First of all I'm guessing that filesystem /www is mapped to http://servername/ root, which means that folder /www/cgi-bin/ maps to http://servername/cgi-bin/ and thus you should be hunting for http://servername/cgi-bin/first.cgi instead.

It also might be that the http server process cannot read, even if you can. The file mode should be 555 (r-xr-xr-x) or 550 (r-xr-x---) depending on if the file group ownership is for the group that httpd is in.

Another possibility is that the $(date) requires a shell-external command, that might not be available at runtime. Do try without that.

Still not working? The server might be picky about where it allows CGI execution. Usually only http://servername/cgi-bin/ is allowed, meaning you're in the right place at filename /www/cgi-bin/first.cgi. uHTTPd documentation seems to want the CGI folder set or else it'll not allow CGI at all. Do check this from the configuration file.

Please note that I'm answering from a generic Unixy background, not knowing very much about OpenWRT or uHTTPd specifics. I do have several decades Unix/Linux background and the generic architecture is very familiar to me.

I'd guess it's the permissions problem - I saw that the poster had used chmod but missed that it didn't include group/others. — Jenny D, Mar 31 '14 at 17:11
(BTW, your name will be appended to every answer and question here, so you don't need to add a sign-off.) — Jenny D, Mar 31 '14 at 17:11
Well, you started out with a very good answer so I should think it won't take very long for you :-) — Jenny D, Mar 31 '14 at 17:53

score 0 · Answer 2 · answered Apr 01 '14 at 22:13

0

The (embarrassing) answer is that I had been using CAT the create the file and pressing Control-Z to finish. Control-Z only pushes the CAT job into the background, so the CAT still had the file open. Using the Control-D keystroke to finish CATing into the file correctly closes the file and gets rid of the "Text File Busy" error.

answered Apr 01 '14 at 22:13

bigjosh

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To detect which programs might have a particular file open, try: `fuser -v /www/cgi-bin/first.cgi` – cpugeniusmv Apr 01 '14 at 22:34

Unable to launch the requested CGI program: /www/cgi-bin/first.cgi: Text file busy

2 Answers2