Tuesday, April 14, 2009

Find length of longest line - awk bash


This is how we can find the length of the longest line in a file.


$ awk ' { if ( length > L ) { L=length} }END{ print L}' file.txt

Output:
25


And also to print the longest line along with the length:


$ awk ' { if ( length > L ) { L=length ;s=$0 } }END{ print L,"\""s"\"" }' file.txt

Output:
25 "136068 sumAQSD.1236800000"


Read about awk built in string manipulation function length

4 comments:

kg23 said...

Output the length of the longest line in a file:
$ wc -L file.txt

Jadu Saikia said...

@kg23, thanks a lot for this. really helpful. never knew about this. thanks

-L, --max-line-length
print the length of the longest line

Mike said...

Note that some (if not many) implementations do not include the "-L" option for wc.

Karan Bohra said...


if='file.txt'
< $if sed 'y/]/./;s/.*/[&]/' |
dc -e "
#####
## get longest line length
#####

#####
# macros
####
[q]sq
[sA]sM
[?z0=qZdlA max length
# register 'l' => line.
?dZsmsl

# computations
lbx

###
## display result
##

# push the fields onto the main stack in reverse
# order from which they need to be printed.
[$QQ$NL]ll[$SP$QQ]lm

# now print the stack
lpx
"

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