UNIX for Dummies Questions & Answers

I have a fixed width file of length 53. when is try to get the lengh of the record of that file i get 2 different answers.

Code:

 
awk '{print length;exit}' <File_name>

The above code gives me length 50.

Code:

 
wc -L <File_name>

The above code gives me length 53.

Please clarify on the above.

Amrutha24,

Code:

wc -L 

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

and the awk code you are using are not the same. This code will print the length of the first line only.

Code:

awk '{print length;exit}'

To print the max length of any line of the file you can use this with awk :

Code:

awk '{if(max=="") {max=length($0)};if(length($0)>max){max=length($0)}}END{print max}'  file

According to the standards, the awk command given should print the number of characters in the 1st line in the file (not counting the trailing newline). But, some buggy versions (including Mac OS X's awk) of awk print the number of bytes instead of the number of characters.

The meaning of wc -L is not defined by the standards and the man pages I've seen that include this options say that -L gives the length of the longest line, but does not specify the units (bytes, characters, etc.), but with wc i'd expect that the count includes the terminating newline character.

When you say you have a fixed width file of length 53, it isn't clear whether you mean each line in the file is 53 bytes, 53 characters, 53 32-bit integers, etc., or a file that is a single line of 53 bytes, characters, ... If your input is encoded using UTF-8, 53 characters could take 53 to 313 bytes. Without knowing the actual contents of your input file, the encoding used to store characters in the file, what characters are contained in the file, the meaning of wc's -L option on your system, whether awk's length on your system counts bytes of characters, and what locale is being used when running the above commands; there isn't much we can do to diagnose what is going on in your specific case.