Shell Programming and Scripting

I am trying to look through a directory where the file names are like this: stringnumber_string, and I want to see if I can take the first part of the name and sort it by the number. I tried this:

Code:

for i in *_; do
	if[-f "$i"]; then
	fileNum=${i%_*};
	echo $fileNum
	fi
done

but it gives me an error. How can I fix this?
And I was trying to use this to sort it:
sort -t _ -k 2 -g ./

Is there a way to put these together to work?
Thanks for any help.

Could you post a representation of:

Code:

ls *_*

or file names that you say
and a copy and paste of the error?

example file names: file54353_04, file34444_04, file12345_04

error: syntax error near unexpected token `then'

I tried taking away the then and fi, but then it gives me this error: if[-f *_]: command not found

Does this do what you want?

Code:

ls *_* | sort -t_ -k2 -g

The error is due to the test, it should be:

Code:

if [ -f "$i" ]; then

It is required to have spaces after and before `[ and ]'.

---------- Post updated at 07:21 PM ---------- Previous update was at 07:13 PM ----------

Also glob (that is the `*_' in the for loop) are implicitly anchored. Meaning that it is the equivalent of start of string followed by pattern followed by end of string.
*_ means to expand to files that start with any or none sequence of character, followed with an underscored followed by end of string. Which it will only hit names ending in `_'

Would I have to use both codes? Or do I use them separately?
And thanks that fixed the problem, but it is not searching into my subdirectories so it is not outputting anything.

Only that

Code:

ls *_* | sort -t_ -k2 -g

or

Code:

ls file*_* | sort -t_ -k2 -g

if file correspond to the real "string" portion of the file

I mean do I put it in the if statement so I can sort it?
Sorry I am pretty new to unix and bash; trying to learn for my new job coming up.