Here is an example input file test.txt: 

D,642,0642,UBF,EVL,,M,,S,S,FOREVER,213,213,
D,642,0642,UBF,EVL,,M,,S,S,QSP-U=C,4,4,
D,642,0642,UBF,EVL,,M,,S,S,123456,4,4,
D,642,0642,UBF,EVL,,M,,S,S,12345,4,4,

[download]
where the fields are separated by a comma. For example, FOREVER above is the eleventh field. This is just a guess based on your description. Please correct me if this is wrong.

Given the above assumption, the following one-liner: 

perl -nlaF/,/ -e 'length($F[10]) < 7 and print' test.txt

[download]
prints to stdout: 
D,642,0642,UBF,EVL,,M,,S,S,123456,4,4,
D,642,0642,UBF,EVL,,M,,S,S,12345,4,4,

[download]
i.e. prints out only those lines where the eleventh field is less than seven characters in length.

See perlrun for details of the -a and -F command line switches to perl.

Once you are happy that works and meets the spec. you could add the -i switch to auto-edit the file.

In reply to Re: perl one liner for csv file one field by eyepopslikeamosquito
in thread perl one liner for csv file one field by MrTEE

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.