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# 8  
Old 06-19-2010
It makes no difference here
Code:
$ ls | grep f*.
abc
def
hij

So what did you mean by "I changed the question a bit but I don't think it would have made any difference..."?
# 9  
Old 06-19-2010
Quote:
Originally Posted by scottn
It makes no difference here
Code:
$ ls | grep f*.
abc
def
hij

So what did you mean by "I changed the question a bit but I don't think it would have made any difference..."?
Here you go

The following command is executed:

$ ls
defer dir1 dir3 file2 fileb flower list script1
defer2 dir2 file1 filea filec fruit output veg
You execute the command:


ls | grep f*.


Which files will be displayed?

A. All of the files. B. Only the files that begin with an f. C. All of the files that contain an f. D. None of the files.







The Answer is showing as



Answer A is incorrect. None of the files will be displayed

Answer B is incorrect. None of the files will be displayed

Answer C is incorrect. None of the files will be displayed

Answer D is correct. None of the files are displayed as the shell has matched the pattern f*, so the command has no output to check against


# 10  
Old 06-19-2010
The answer may or may not be correct.

If the dot is actually part of the question, as you said, then the answer is wrong - regardless of globbing.

If the dot is not part of the question and globbing is on, then the answer is correct.

Code:
$ set +f # globbing is on
$ ls | grep f*.
defer
defer2
dir1
dir2
dir3
file1
file2
filea
fileb
filec
flower
fruit
list
output
script1
veg

$ ls | grep f*
(no output)

$ set -f

$ ls | grep f*.
defer
defer2
dir1
dir2
dir3
file1
file2
filea
fileb
filec
flower
fruit
list
output
script1
veg

$ ls | grep f*
defer
defer2
dir1
dir2
dir3
file1
file2
filea
fileb
filec
flower
fruit
list
output
script1
veg

# 11  
Old 06-19-2010
thanks for that....I'm going to have a think about it down the pub!
# 12  
Old 06-21-2010
Code:
Where there are no files which match the pattern "f*." shell expands this to a null string. Thus:
ls | grep f*.

Expands to
ls | grep ''

Which lists all files.


A file in the directory with a name starting with "f" and ending in "." changes the behaviour.
# 13  
Old 06-21-2010
Quote:
Originally Posted by methyl
Code:
Where there are no files which match the pattern "f*." shell expands this to a null string. Thus:
ls | grep f*.
 
Expands to
ls | grep ''
 
Which lists all files.


A file in the directory with a name starting with "f" and ending in "." changes the behaviour.
I just created a file starting with "f" and ending in "." and it does appear to change the behaviour...but can you tell me why that is?

thanks
# 14  
Old 06-26-2010
I just had a look at some other questions and none of them end in a period....so the dot at the end of the above question is intentional!
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