Collect all kinds of awk programming exceptions and fault solutions.


How to reject strings that are starting with some text in awk?

I want to accept strings that are not starting with "::1" in /etc/hosts file using the below awk script:
cat /etc/hosts | awk '/~(^::1)/{print}' >> test.txt
But the above code acce...


Use awk to convert an .ini file to .csv format

I am new to shell scripting, I have an .ini file like this
[tag]
column1 = a1
column2 = a2
column3 = a3
[tag]
column1 = b1
column2 = b2
column3 = b3
and I want to ...


AWK to join next row without removing it

I'm using the following command to join the next row in a csv but would like do it without removing the rows.
awk 'NR%2{printf "%s, ",$0;next;}1' test.csv
Test.csv
rabbit
cat
dog
turtle
...


AWK join next 2 rows from csv

I'm using the following command to join the next row but would like to join the next 2 rows
awk -v OFS=', ' 'NR==1{first=$0} NR>1{print prev, $0} {prev=$0} END{print prev, first}' test.csv
test...


How do I match a pattern and then copy multiple lines?

I have two files that I am working with. The first file is a master database file that I am having to search through. The second file is a file that I can make that allows me to name the items fr...


How do I insert a blank line every n lines using awk?

I've got an input file like this:
line 1
line 2
line 3
line 4
line 5
line 6
I'd like to use awk to insert a blank line every few lines; for example, every two:
line 1
line 2
line 3
line 4
line 5


How do I insert a blank line every n lines using awk?

I've got an input file like this:
line 1
line 2
line 3
line 4
line 5
line 6
I'd like to use awk to insert a blank line every few lines; for example, every two:
line 1
line 2
line 3
line 4
line 5


How to add a blank line before the first line in a text file with awk

I have some text files. I would like to add a blank line before the first line in each text file. How can I do this with awk?