One problem you will have, if you try to update files 2, is that you can not write a new, longer line, into the middle of file 2, without overwriting the following data:

# Original file 2:
Bloggs,Fred\n
Conner,Sarah\n
Bloggs,Joe\n

# file 2 after adding Fred's phone Number
Bloggs,Fred,0234687821\n
h\n
Bloggs,Joe\n

[download]
As you can see, poor old Sarah Conner, has been terminated. Follow the advice to build a new file, and if required remove (or rename) the old file 2, and rename the new one, to the original name, when done.

Cheers,
R.

Pereant, qui ante nos nostra dixerunt!

In reply to Re^2: Write in files by Random_Walk
in thread Write in files by lolz

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.