This is a test
Giving back more than we take
I want my input file with the following output:
a test
more than we take
How do I printing lines from the nth field using awk under UNIX or Linux operating systems?
You can use the awk command as follows. The syntax is as follows to skip first two fields and print the rest (thanks danliston):
awk '{ $1=""; $2=""; print}' filename To skip first three fields, enter:
awk '{ $1=""; $2=""; $3=""; print}' filenameYou can specify the input field separator too. In this example use ‘:’ as the the input field separator:
awk -F':' '{ $1=""; $2=""; print}' filenameOld solution
My old solution to skip first two fileds and print the rest of line:
echo 'This is a test' | awk '{print substr($0, index($0,$3))}'
You can also use substr:
substr(s, i [, n])
It return the at most n-character substring of s starting at i. If n is omitted, use the rest of s. So:
awk '{print substr($0, index($0,$3))}' <<< 'This is a test'
You can also use the cut command:
echo 'This is a test' | cut -d ' ' -f3-
cut -d ' ' -f3- <<<'This is a test'
Finally, process the file using bash while loop:
#!/bin/bash _input="/path/to/file.name.txt" while IFS= read -r line do cut -d ' ' -f3- <<<"$line" ### same stuff with awk ### ### awk '{print substr($0, index($0,$3))}' <<< "$line" ### done < "${_input}" |
How to create HTML table using awk
Say you have data as follows in a text file called data.txt:
-v Show version -d Set delta value -o Set output file name -i Set input filename for this command
To create html table code run:
awk 'BEGIN{ print "<table>"} { printf "<tr><td>%s</td><td>", $1; $1=""; print $0 "</td></tr>"} END{ print "</table>"}' data.txt |
Sample session:
Please note that you can also use Perl, Python or other shell text processing commands to do the same thing.
10 comment
thanks.. this is the most elegant, simplest and my preferred way of doing this. The other way of doing this is with awk’s NF variable in a for-loop. This non-trivial situation is best explained in http://awk.freeshell.org/RangeOfFields.
Very useful, thanks. I went for the first Awk option to trim the permissions and filesize off the output of ls -l
Didn’t know about cut. Time to read the man page! :-)
The awk method works perfectly well if the first three fields are unique. However, if your string was as follows:
“This This This will break the awk method”
…. the output will be unchanged since when it indexes the third field, it finds the first.
The cut method works perfectly well as long as your fields are not separated by more than a single space. It treats multiple spaces as separate fields.
Awk… how I love thee.
If in 9th field($9) there is sth like: A/B/C and one needs C. how can we extract C and put it in output?
I see this thread is a few years old, but I could not resist adding for the sake of searching the internet for a simple (but less elegant) answer.
awk '{ $1=""; $2=""; print}' filename
The above simply uses the default field separator, replaces the content of the first two fields with “nothing”, and prints the modified line. No need to use redirection, awk expects a file as input.
Note1: The field separators are left in tact, so your output lines begin with two blank spaces. This can be compensated for using substr($0,3) behind the print command.
Note2: The advantage to this syntax, is “any” field(s) may be ommitted, not just the first X number of fields.
Excellent Mr. danliston , this was easy and powerful.
Appreciate your comments.
Thanks. The faq has been updated.
The with this approach is that it prints leading spaces – the substr() way doesn’t.
sed -n ‘3,$’p infile.txt