Hi,
I am a new learner of join command. Some result really make me confused.
Please kindly help me.
input:
file1:
LEO oracle engineer 210375
P.Jones Office Runner ID897
L.Clip Personl Chief ID982
S.Round UNIX admin ID6
file2:
Dept2C ID897 6 years
Dept5Z ID982 1 year
Dept3S ID6 2... (1 Reply)
example sql:
select a.a1,b.b1,c.c1,d.d1,e.e1
from a
left outer join b on a.x=b.x
left outer join c on b.y=c.y
left outer join d on d.z=a.z
inner join a.t=e.t
I know how single outer or inner join works in sql.
But I don't really understand when there are multiple of them.
can... (0 Replies)
joining two files:
File1:
-----
1|M
2|M
3|F
File2:
-----
1|abc|def
3|xyz|pqr
join -t '|' 1.txt 2.txt gives(Itried many other ways)
1|M|abc|def
3|F|xyz|pqr
but I need the result like following (14 Replies)
I want basically to merge two config files each of them look like that
File:Option1 value1
Optionx valuex
....
One of those files is default config while the other is generated by my script. Now here is the problem, when my script generates an option that previously has been set by default i... (4 Replies)
Hello,
My apologies if this has been posted elsewhere, I have had a look at several threads but I am still confused how to use these functions. I have two files, each with 5 columns:
File A: (tab-delimited)
PDB CHAIN Start End Fragment
1avq A 171 176 awyfan
1avq A 172 177 wyfany
1c7k A 2 7... (3 Replies)
Hi,
I have 20 tab delimited text files that have a common column (column 1). The files are named GSM1.txt through GSM20.txt. Each file has 3 columns (2 other columns in addition to the first common column).
I want to write a script to join the files by the first common column so that in the... (5 Replies)
Hello,
This post is already here but want to do this with another way
Merge multiples files with multiples duplicates keys by filling "NULL" the void columns for anothers joinning files
file1.csv:
1|abc
1|def
2|ghi
2|jkl
3|mno
3|pqr
file2.csv:
1|123|jojo
1|NULL|bibi... (2 Replies)
Discussion started by: yjacknewton
2 Replies
LEARN ABOUT DEBIAN
path::class::file::stat
Path::Class::File::Stat(3pm) User Contributed Perl Documentation Path::Class::File::Stat(3pm)NAME
Path::Class::File::Stat - cache and compare stat() calls on a Path::Class::File object
SYNOPSIS
use Path::Class::File::Stat;
my $file = Path::Class::File::Stat->new('path','to','file');
# $file has all the magic of Path::Class::File
# sometime later
if ($file->changed)
{
# do something provocative
}
DESCRIPTION
Path::Class::File::Stat is a simple extension of Path::Class::File. Path::Class::File::Stat is useful in long-running programs (as under
mod_perl) where you might have a file handle opened and want to check if the underlying file has changed.
METHODS
Path::Class::File::Stat extends Path::Class::File objects in the following ways.
use_md5
Calling this method will attempt to load Digest::MD5 and use that instead of stat() for creating file signatures. This is similar to how
File::Modified works.
changed
Returns the previously cached File::stat object if the file's device number and inode number have changed, or if the modification time or
size has changed.
Returns 0 (false) otherwise.
While File::Modified uses a MD5 signature of the stat() of a file to determine if the file has changed, changed() uses a simpler (and
probably more naive) algorithm. If you need a more sophisticated way of determining if a file has changed, use the restat() method and
compare the cached File::stat object it returns with the current File::stat object.
Example of your own changed() logic:
my $oldstat = $file->restat;
my $newstat = $file->stat;
# compare $oldstat and $newstat any way you like
Or just use File::Modified instead.
restat
Re-cache the File::stat object in the Path::Class::File::Stat object. Returns the previously cached File::stat object.
The changed() method calls this method internally if changed() is going to return true.
SEE ALSO
Path::Class, Path::Class::File, File::Signature, File::Modified
AUTHOR
Peter Karman, <karman@cpan.org>
COPYRIGHT AND LICENSE
Copyright (C) 2006 by Peter Karman
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
perl v5.14.2 2012-01-28 Path::Class::File::Stat(3pm)