Re: Reading from a file

are you running on linux?

my $first_line = qx/head -1 $filename/;
print $first_line;

my $last_line = qx/tail -1 $filename/;
print $last_line;

my $n = 100;
my $nth_line = qx/tail +$n $filename | head -1/;
print $nth_line;
[download]

-hth

Comment on Re: Reading from a file Download Code

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Re^2: Reading from a file by just dave (Acolyte) on May 23, 2006 at 12:11 UTC
Hello and thank you all! A few answers: 1. yes, I'm running on linux !! 2. this is a reporter file, it gets appended all the time, every minute or so 3. the last line is the most updated(since the report row /line is added every minute), that's why I'm interested in it, and I used to read the first line too since it holds the columns name(I get the data by the column name) BUT now I found a bug- if a change is made, and a column is added,then a new row is added (similar to the first row holding the names) but this row also holds the name of the new column, BUT it doesn't know about it since it reads the column name from the first row in the file So, I need to change this and search the file for this row and if it's not found-I'll end up with the first one It look something like this: `#name: time input output users connected ... 12:23 23 34 780 560 12:24 21 40 780 570 ....` [download]	[reply] [d/l]
Re^3: Reading from a file by LanceDeeply (Chaplain) on May 23, 2006 at 13:44 UTC
ok- in keeping with the *nix commands theme how about: `# # find last row that defines the columns ( i.e. starts with #name: ) # my $column_names = qx/grep ^\#name $filename \| tail -1/; print $column_names;` [download] -hth	[reply] [d/l]