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Full Discussion: Check for null values in a column
Top Forums UNIX for Dummies Questions & Answers Check for null values in a column Post 302303695 by nephros on Friday 3rd of April 2009 09:46:49 AM
Old 04-03-2009
Quote:
Originally Posted by vgersh99
Code:
nawk -F, '{if ($8 == "") print "Line", NR, "REJECTED" }' file

Which does the exact same thing unless I'm missing something.
(I do admit that
Code:
 nawk 'BEGIN { FS="," } {foo}'

would have been better.)

Anyway it's a matter of taste, I prefer to set FS inside the script because it's a bit more flexible wrt more complex separators. But it really does not matter for the CSV above.

EDIT: I stand corrected. Behaviour of my original version is highly dependant on the awk implementation used. I works in /usr/bin/nawk from Solaris 10.
Just checked with The One True awk, and my original version does not work there. vgersh99s version and the BEGIN block variation do.
Last edited by nephros; 04-03-2009 at 11:02 AM..
 

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LEARN ABOUT XFREE86

ucblinks

ucblinks(1B)					     SunOS/BSD Compatibility Package Commands					      ucblinks(1B)

NAME

       ucblinks - adds /dev entries to give SunOS 4.x compatible names to SunOS 5.x devices

SYNOPSIS

       /usr/ucb/ucblinks [-e rulebase] [-r rootdir]

DESCRIPTION

       ucblinks  creates symbolic links under the /dev directory for devices whose SunOS 5.x names differ from their SunOS 4.x names. Where possi-
       ble, these symbolic links point to the device's SunOS 5.x name rather than to the actual /devices entry.

       ucblinks does not remove unneeded compatibility links; these must be removed by hand.

       ucblinks should be called each time the system is reconfiguration-booted, after any new SunOS 5.x links that are needed have been  created,
       since the reconfiguration may have resulted in more compatibility names being needed.

       In  releases prior to SunOS 5.4, ucblinks used a  nawk rule-base to construct the SunOS 4.x compatible names. ucblinks no longer uses  nawk
       for the default operation, although  nawk rule-bases can still be specifed with the -e option.  The  nawk rule-base equivalent to the SunOS
       5.4 default operation can be found in /usr/ucblib/ucblinks.awk.

OPTIONS

       -e rulebase     Specify rulebase as the file containing nawk(1) pattern-action statements.

       -r rootdir      Specify rootdir as the directory under which dev and devices will be found, rather than the standard root directory /.

FILES

       /usr/ucblib/ucblinks.awk        sample rule-base for compatibility links

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWscpu			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       devlinks(1M), disks(1M), ports(1M), tapes(1M), attributes(5)

SunOS 5.10							    13 Apr 1994 						      ucblinks(1B)
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