I am new to awk and need some help
this works
awk '{
for(i =0;i<10;i++){
if ($27 == 'addr1') {
print >"temp.csv"
}
}
}' /tmp/input.csv
i tried below and is not working, how to pass count value from outside to awk command
count=10
echo $count
awk '{
for(i =0;i<count;i++){
if ($27 == 'addr1') {
print >"temp.csv"
}
}
}' /tmp/input.csv
Use the -v option to set a variable inside awk:
awk -v count="$count" '...'
"Filename" arguments of the form X=Y are also interpreted as variable assignments. The following should work:
awk '...' count="$count" /tmp/input.csv
If you want compare against a string inside awk, you need double quotes around the string. Like
awk -v count=$count '
$27=="addr1" {
for(i=0;i<count;i++)
print > "temp.csv"
}' /tmp/input.csv
(Note that for instance 'if ($27 == 'addr1')' will expand to 'if ($27 == addr1)', that is: addr1 without double quotes)
If you instead want compare against the shell variable $addr1 inside awk, you can do
awk -v count=$count -vaddr1="$addr1" '
$27==addr1 {
for(i=0;i<count;i++)
print > "temp.csv"
}' /tmp/input.csv
You use the -v argument to awk to pass in values from the outside as awk variables.
count=2
echo $count
awk -vcount=$count '{
for(i =0;i<count;i++){
if ($27 == 'addr1') {
print >"temp.csv"
}
}
}' /tmp/input.csv
You can use a simply trick : break the awk code enclosure (single quotes) to put what you want inside, a piece of embedded code.
> a=10
> awk 'BEGIN{for (i=0;i<='${a}';i++){printf("%d ", i)}}'
0 1 2 3 4 5 6 7 8 9 10
The good: Simple and handy.
The bad: It makes your program less readable .
"addr1"?