Running *nix commands in embedded script

I'm having problems getting system commands to execute in an embedded shell script. For example, if Hazel detects a DJVU file in a folder, I want it to execute "djvu2pdf $1". However, I always get an error (status code 127 which, I think, means the shell command can't be found). If I manually execute "djvu2pdf [filename]" in Terminal, it works as expected, since djvu2pdf (and all other system commands) are in directories in $PATH.

I managed to get a command working by installing it to the folder Hazel is monitoring, but this isn't a solution.

How can I get Hazel to detect and run shell commands?

Cheers.

Last edited by a_freyer on Sun Jul 22, 2012 3:19 pm, edited 1 time in total.

The solution you found evidences the issue; Hazel executes the command from a different location than terminal.

Here's a better solution than copying the executable into the monitored directory:

Step 1: Find where you command exists

Open terminal and type "whereis thecommandtorun" where thecommandtorun is replaced by the command that you want to run (djvu2pdf). For instance, if I wanted to find where awk is, I'd type:

Code: Select all: Andrews-MacBook-Air:~ andrewfreyer$ whereis awk /usr/bin/awk

The result is the full path to awk.

If the "whereis" command fails to find your executable, you can try "which" as well.

Hint: If you type whereis awk | pbcopy the full path will be copied directly to the clipboard.

Step 2: Prepend the path in the embedded script within Hazel

Before in Hazel:

Code: Select all: myCustomBinaryForUseWithHazel $1

After in Hazel:

Code: Select all: /usr/bin/myCustomBinaryForUseWithHazel $1

Thanks for the detailed reply. I should've mentioned that I had tried specifying the full path to the executable in Hazel, with no luck.

I use Homebrew, which installs packages to /usr/local/. For some reason, whereis doesn't return anything for any of my Homebrew-installed utilities.

For example, although for awk I get the expected

Code: Select all: MBA:~ fort$ whereis awk /usr/bin/awk MBA:~ fort$

for djvu2pdf (and all other brews), I get

Code: Select all: MBA:~ fort$ whereis djvu2pdf MBA:~ fort$

I've also tried adding a symlink to the executable in the watched folder, but this doesn't work either.

Full path should be what solves your problem. Perhaps you could change the shell to bash (/bin/bash) over bourne (/bin/sh)?

Another possibility for the problem is character escaping.

From your OP it looks like you're doing this:

Code: Select all: /path/to/command $1

When you should be doing this:

Code: Select all: /path/to/command "$1"

Still no luck. This is the only line in my embedded script:

Code: Select all: /usr/local/Cellar/djvu2pdf/0.9.2/bin/djvu2pdf "$1"

but I'm still getting an error - this time it's status code 1. Any idea what it might mean?

Code: Select all: 2012-07-22 21:19:15.478 hazelworker[45496] 2012-05-30.djvu: Rule djvu2PDF matched. 2012-07-22 21:19:15.991 hazelworker[45496] [Error] Shell script failed: Error processing shell script on file /Users/fort/Documents/DocumentLibrary/Word2Papers/2012-05-30.djvu. 2012-07-22 21:19:15.998 hazelworker[45496] Shellscript exited with non-successful status code: 1

Last edited by a_freyer on Sun Jul 22, 2012 5:04 pm, edited 1 time in total.

I'm assuming that when you run command /Users/fort/Documents/DocumentLibrary/Word2Papers/2012-05-30.djvu in terminal, the error is not present?

Its also possible that the status code of 1 for the script is success. Was the PDF created for that file?

a_freyer wrote:I'm assuming that when you run /Users/fort/Documents/DocumentLibrary/Word2Papers/2012-05-30.djvu in terminal, the error is not present?

Right. Actually, the command would be djvu2pdf 2012-05-30.djvu.

a_freyer wrote:Its also possible that the status code of 1 for the script is success. Was the PDF created for that file?

Unfortunately not

This is the exact line that Hazel is executing:

/usr/local/Cellar/djvu2pdf/0.9.2/bin/djvu2pdf "/Users/fort/Documents/DocumentLibrary/Word2Papers/2012-05-30.djvu"

Does this work in terminal, or does this spit an error?

Looking at the source for your converter, it seems like a full path for the file should work fine.

Further, it looks like its creating your PDF in the temp directory. Do you have write access there?

Another user had a similarly inexplicable problem a few weeks ago. He re-installed Hazel for all users and that solved his issue.

a_freyer wrote:This is the exact line that Hazel is executing:

/usr/local/Cellar/djvu2pdf/0.9.2/bin/djvu2pdf "/Users/fort/Documents/DocumentLibrary/Word2Papers/2012-05-30.djvu"

Does this work in terminal, or does this spit an error?

It works in terminal and produces the PDF.

a_freyer wrote:Looking at the source for your converter, it seems like a full path for the file should work fine.

Further, it looks like its creating your PDF in the temp directory. Do you have write access there?

Are you talking about /private/tmp? I do have write access to all but one of the folders in it but, anyway, when I execute djvu2pdf in the terminal, the PDF is created on my desktop.

a_freyer wrote:Another user had a similarly inexplicable problem a few weeks ago. He re-installed Hazel for all users and that solved his issue.

Thanks! I'll try that tomorrow. Now...to bed.

I reinstalled Hazel for all users (it was previously installed for my user account only) but am still getting the error

This makes no sense...

I'll try a clean install, after backing up my rules.

I'd next add some debug logging to the executable to see which exit 1 is tripping via hazel.

The clean install made no difference, so...

a_freyer wrote:I'd next add some debug logging to the executable to see which exit 1 is tripping via hazel.

Here's the debug log I get when I drop a .djvu file into Word2Papers:

https://www.dropbox.com/s/l0nv50nbc6yv544/hazelDebug.log