UNIX Desktop Questions & Answers

Hi

please can someone help me with a query?

The following command is executed:

$ ls
abc def hij

You execute the command:

ls | grep f*.

Which files will be displayed and why?

thanks

This sounds like homework.

Please read the The UNIX and Linux Forums - Forum Rules

And why not just run the command, do some testing, and see for yourself....

No, not homework.... but I don't agree with one of the answers in SCSAS Unix associate sample questions. I have contacted Sun but they just reply with some crap. I have run the command on a BSD (since I don't have access to SOLARIS) platform and it does appear that their answer is incorrect...I guess I am just looking for confirmation.

All the files will be displayed because the asterisk is matching zero repetitions of the 'f' character and the '.' is matching any single character

And what does their answer say?

"None of the files are displayed as the shell has matched the pattern f*, so the command has no output to check against"

I changed the question a bit but I don't think it would have made any difference...

If globbing is on, the shell will expand f* to all files starting with f. If there is one such file, it will be displayed. If there's more, then the grep will return nothing. If there's none, grep will match 0 or more f's

If globbing is off, then grep will match 0 or more f's.

Code:

$ set +f
$ touch abc def hij
$ ls | grep f*
abc
def
hij

$ touch fgh
$ ls | grep f*
fgh

$ touch fgh2
$ ls | grep f*

$ set -f
$ ls | grep f*
abc
def
fgh
fgh2
hij

I'd say their answer is wrong?

The actual question also has a point/dot at the end!...