How am I editting and running two different files?

AncientPC · 05-09-2008, 03:17 PM

I have a test script in ~/bin/test.

I have an old test script that contains the lines:
#!/bin/bash
echo "test 0"
exit 0

When I type in "which test" it gives me:
/home/user/bin/test

I then type in "vim `which test`" and modify and save a single line:
#!/bin/bash
echo "test 1"
exit 0

The command: cat `which test` returns the output:
#!/bin/bash
echo "test 1"
exit 0

When I run test, this is the output:
test 0

The command: ~/./bin/test returns the output:
test 1

Why?!?

DiBosco · 05-09-2008, 03:42 PM

Because typing vim which test has created a file called which test presumably. Why did you type "vim which test" and not just "vim test"? The only problem with that theory is that you seem to infer typing "vim which test" brought up a file you could modify.

I just don't understand "vim which test".

PTrenholme · 05-09-2008, 04:04 PM

Quote:

Originally Posted by DiBosco

Because typing vim which test has created a file called which test presumably. Why did you type "vim which test" and not just "vim test"? The only problem with that theory is that you seem to infer typing "vim which test" brought up a file you could modify.

I just don't understand "vim which test".

Um, note the back-quotes around the which test meaning "the string returned by the the command."

As to the question asked by AncientPC, try a find ~/ | grep test to see if you have other copies of the test script laying around.

AncientPC · 05-09-2008, 04:09 PM

"find ~/ | grep test" returns a single file: /home/user/bin/test

DiBosco · 05-09-2008, 05:30 PM

Quote:

Originally Posted by PTrenholme

Um, note the back-quotes around the which test meaning "the string returned by the the command."

As to the question asked by AncientPC, try a find ~/ | grep test to see if you have other copies of the test script laying around.

Don't know what a back quote is, but I guess you mean the single inverted commas inside the dual ones. I had tried doing the same thing on scripts I had to see whether I could replicate it, but typing:

vim 'which myscriptname'

or:

vim which myscriptname

just opened up a blank vi session either named which or which myscriptname so I'd assumed the different styles of inverted commas were just for emphasis. Sorry for being thick.

Still don't understand it, what it's supposed to do and why I'm opening up black sessions.

fbianconi · 05-09-2008, 06:27 PM

Is the file needed to be named 'test' ?
Since it's a very generic name it could be calling different things when you run 'test' on command line, give it a try on 'which -a test' also 'env | grep test' to see if it has been redefined in your environment. Read bash man pages (you're using bash don't you?), I'm sure that has a builtin function named 'test' but I think it doesn't print anything

AncientPC · 05-09-2008, 06:39 PM

Quote:

Originally Posted by DiBosco

Don't know what a back quote is, but I guess you mean the single inverted commas inside the dual ones. I had tried doing the same thing on scripts I had to see whether I could replicate it, but typing:

vim 'which myscriptname'

or:

vim which myscriptname

just opened up a blank vi session either named which or which myscriptname so I'd assumed the different styles of inverted commas were just for emphasis. Sorry for being thick.

Still don't understand it, what it's supposed to do and why I'm opening up black sessions.

A backquote is the quote underneath the ~ key.

It basically evaluates what's between the ` ` before passing it on. For example, I could be redundant and type "ssh `whoami`@server.com" and it would evaluate to "ssh user@server.com" before running it.

Quote:

Originally Posted by fbianconi

Is the file needed to be named 'test' ?
Since it's a very generic name it could be calling different things when you run 'test' on command line, give it a try on 'which -a test' also 'env | grep test' to see if it has been redefined in your environment. Read bash man pages (you're using bash don't you?), I'm sure that has a builtin function named 'test' but I think it doesn't print anything

I've just renamed files for the sake of the forums. In reality, it's called rs-backup.sh and there is not another file that's named the same on the system but the same circumstances / problems apply as above.

AncientPC · 05-09-2008, 08:25 PM

I feel retarded and have just found the problem, I've aliased test to something else.

introuble · 05-10-2008, 02:31 AM

LOL, nice one, will have to remember that for the next LUG meeting.

PTrenholme · 05-10-2008, 07:12 AM

Also, remember that test is a BASH "built-in" function, so writing your own executable called test may cause scripts that rely on the test built-in function may produce "unexpected" results.