I want to do a line count and get the number into a variable in a shell script. For eg.
wc -l filename.dat
gives 221 filename.dat
I want to grep '221' into a variable, which I could use later.
Can this be done in a single statement ? I don't want to copy the output of wc -l into another file and then grep.
You can pass the filename to the STDIN of wc to get only the number of lines :
wc -l <filename.dat
To save it as a variable :
var="$(wc -l <filename.dat)"
Example :
$ wc -l foo.txt
12 foo.txt
$ wc -l <foo.txt
12
$ var="$(wc -l <foo.txt)"
$ echo "$var"
12
Note that as Stéphane Chazelas has pointed out, some wc variants might add spaces before and after the number of lines to get desired alignment.
wc implementations (typically the traditional ones) insert spaces before and after the number (to right-align on a 8 character column: ␣␣␣␣␣12␣)
– Stéphane Chazelas
Sep 9 '15 at 20:16
