AWK User defined Function / Field Separators

Program I User defined Function

awk '
BEGIN{i=1}
{
my_function(i)
print line[i]

i=i+1
}
function my_function(i)
{

if (i==1)

{
print "First"

line[1]= "awk"

}

if (i==2)

{
print "Second"

line[2]= "gawk"

}

if (i==3)

{
print "Third"

line[3]= "nawk"

}

}' filename

Field separators

• FS="\t+"

• FS="[[:space:]]+"

Number of fields

• NF == 3 
  
  
  
  
  
  
  { print "this particular record has three fields: " $0 }

• if ( NF > 2 ) {

print $1 " " $2 ":" $3 

 

}

Record number 

 

The record number (NR) is another handy variable. It will always contain the number of the current 

record (awk counts the first record as record number 1).

if (NR < 10 ) || (NR > 100) 

{ print "We are on record number 1-9    or 101+" }

 

if ( NR > 10 ) {

print "ok, now for the real information!"

}

Multiline records

 

Jimmy the Weasel

100 Pleasant Drive

San Francisco, CA 12345

Big Tony

200 Incognito Ave.

Suburbia, WA 67890

-----------------------

BEGIN {

FS="\n"

RS=""

}

{ print $1 ", " $2 ", " $3 }

Answer : //Printing in the single for multi-line records.

Jimmy the Weasel, 100 Pleasant Drive, San Francisco, CA 12345

Big Tony, 200 Incognito Ave., Suburbia, WA 67890

OFS and ORS

Output field Separator , Output record separator

BEGIN {

 

FS="\n"

RS=""

OFS=", "

}

{ print $1, $2, $3 }

-------------------------

BEGIN { 

 

FS="\n"

 

RS=""

 

ORS=""

 

}

 

{ 

 

x=1

 

while ( x<NF ) { 

 

 

print $x "\t" 

 

x++

 

}

 

print $NF "\n" 

 

}

--------------------------------------------------------------------------------------


Awk Loop Statement

awk 'BEGIN { i=0 }
{   for(i=0;i<=10;i++)
{
  printf("%d\n", i);
} }'