Beefy Boxes and Bandwidth Generously Provided by pair Networks
Think about Loose Coupling
 
PerlMonks  

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??

You really should have tested it:

  • -e should be immediatelly followed by the script to run,
  • -p prints the current line, so you don't have to do it yourself, -n is what you want in this case.

This (tested!) script would work as:

perl -i.bak -n -e"print if(m/foo/);" foo.txt bar.txt baz.txt

From perldoc perlrun:

-n causes Perl to assume the following loop around your program, which makes it iterate over filename arguments somewhat like sed -n or awk: LINE: while (<>) { ... # your program goes here } "BEGIN" and "END" blocks may be used to capture control before or after the implicit program loop, just as in awk. -p causes Perl to assume the following loop around your program, which makes it iterate over filename arguments somewhat like sed: LINE: while (<>) { ... # your program goes here } continue { print or die "-p destination: $!\n"; } If a file named by an argument cannot be opened for some reason, Perl warns you about it, and moves on to the next file. Note that the lines are printed automatically. An error occurring during printing is treated as fatal. To suppress printing use the -n switch. A -p overrides a -n switch. "BEGIN" and "END" blocks may be used to capture control before or after the implicit loop, just as in awk.

In reply to Re: Re: Re: Large file processed line by line by mirod
in thread Large file processed line by line by sdyates2001

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



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others having an uproarious good time at the Monastery: (5)
As of 2024-03-28 17:31 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found