this is obsolete doc -- see http://doc.nethence.com/ instead

AWK examples 

Usage 

To execute some AWK code, 

awk '{code here}'

awk -F'delimiter' '{code here}'

awk '  BEGIN {preproc code here}

  {code here}

  END {postproc code here}'

Propeller 

To make a propeller acting on stdin, 

BEGIN {split("|#/#-#\\", p, "#"); i = 1} 

{ 

printf("%c\b", p[i++]); 

if (i > 4) {i = 1;}; 

} 

END {printf(" done\n");} 

IP/shortmask 

On Linux systems, print IP and short form netmask, 

        /sbin/ifconfig -a \

        | awk '/inet addr/ {

                ip=gensub(/.*inet addr:([0-9.]+).*/,"\\1","");

                mask=gensub(/.*Mask:([0-9.]+).*/,"\\1","");

                split(mask,V,".");

                n=0;

                for(i=1; i<=4; i++) {

                        while(V[i]) {

                                n+=V[i]%2;

                                V[i]=int(V[i]/2);

                        };

                };

                print ip "/" n}'

Miscellaneous 

To delete the last field from a record, 

echo "1 2 3" | awk '{$NF=""}{print}'

References 

AWK by example : http://www.ibm.com/developerworks/linux/library/l-awk1.html 

Reference : http://www.gnu.org/software/gawk/manual/ 

FAQ : http://hibernia.jakma.org/~paul/awk-faq.html 

Tutorial : http://www.grymoire.com/Unix/Awk.html | Wiki: http://awk.freeshell.org/ 

(FR) A few examples : http://www.epons.org/awk.php 

AWK Tail : http://student.northpark.edu/pemente/awk/awktail.txt 

Freenode #awk wiki : http://awk.freeshell.org/ 

Alfred Aho interview : http://www.computerworld.com.au/index.php/id;1726534212;pp;1;fp;;fpid;