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# 1  
Old 07-13-2012
question about awk
given this:

Code:
[root@vblnxsrv02 setup]# ls -1 /dev/sd[b-z]
/dev/sdb
/dev/sdc
/dev/sdd
/dev/sde
/dev/sdf

returns a list of devices I want to use as input for some other operations. So ...

Code:
[root@vblnxsrv02 setup]# ls -1 /dev/sd[b-z] | awk '{FS="/"; print $3 }' 
 
sdc
sdd
sde
sdf
[root@vblnxsrv02 setup]#

Where I should get sdb, I get a blank line ... everything after is exactly what I want.

When this part is working, I plan to expand it a bit to

Code:
ls -1 /dev/sd[b-z] | awk '{FS="/"; print "some text " $3 " some more text" }' >> afile.lis

I'm open to either tweaking the above or an entirely different approach.
Last edited by Scott; 07-13-2012 at 01:29 PM.. Reason: Code tags
# 2  
Old 07-13-2012
I've never used the awk notation you did, but for some reason it's separating oddly:

Code:
$ cat test| awk '{FS="/"; print $3}'

sdc
sdd
sde
sdf
$ cat test| awk '{FS="/"; print $2}'

dev
dev
dev
dev
$ cat test| awk '{FS="/"; print $1}'
/dev/sdb

That said, I normally use the -F flag for awk (Which does work):
Code:
$ cat test| awk -F'/' '{print $3}'
sdb
sdc
sdd
sde
sdf

# 3  
Old 07-13-2012
Used cut instead of awk. Not sure why "awk" doesn't list the first one.
Maybe someone with superiour UNIX knowledge can help here.
Code:
ls /dev/sd[b-z] | cut -f3 -d "/" | awk '{print "some text" $1 "some other text" }'

This User Gave Thanks to aster007 For This Post:
edstevens
# 4  
Old 07-13-2012
The problem is that you aren't setting the value of FS until _after_ the first record has already been read and split. That first line is being split on whitespace. Since there is none, $3 is empty.

You can use the -F/ option, or set FS in a BEGIN block, or set FS on the command line before the file is named:
Code:
awk -F/ '{ print $3 }'
awk 'BEGIN { FS="/" } { print $3 }'
awk '{ print $3 }' FS=/

Regards,
Alister
These 3 Users Gave Thanks to alister For This Post:
aster007 shaan4uster Vryali
# 5  
Old 07-13-2012
Aster007 - perfect. Thank you so much.
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