I have to join(no other command is allowed) 3 files together. And im aware that i have to sort these files(file1 file2 file3) first before I can join them.
However i have to output these sorted files to some temporary file. i can't just do sort -n file1 > file1 or i get an empty file output. Is there a way to join 3 files without using a other files(temp files etc) other than the 3 files I'm using to join together.
The way im doing it requires the temp files. so in short it'd be like
Last edited by Franklin52; 04-28-2010 at 02:53 AM..
Reason: Please use code tags!
Just a super quick question:
how do you put a link in your php code.
I want to make a link to something in /tmp directory.
i.e. how do you put a href into php, I think it's done a bit differently.
thanks
john (1 Reply)
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020B25 ef-456-e
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Discussion started by: ajay41aj
6 Replies
LEARN ABOUT DEBIAN
plan9-join
JOIN(1) General Commands Manual JOIN(1)NAME
join - relational database operator
SYNOPSIS
join [ options ] file1 file2
DESCRIPTION
Join forms, on the standard output, a join of the two relations specified by the lines of file1 and file2. If one of the file names is the
standard input is used.
File1 and file2 must be sorted in increasing ASCII collating sequence on the fields on which they are to be joined, normally the first in
each line.
There is one line in the output for each pair of lines in file1 and file2 that have identical join fields. The output line normally con-
sists of the common field, then the rest of the line from file1, then the rest of the line from file2.
Input fields are normally separated spaces or tabs; output fields by space. In this case, multiple separators count as one, and leading
separators are discarded.
The following options are recognized, with POSIX syntax.
-a n In addition to the normal output, produce a line for each unpairable line in file n, where n is 1 or 2.
-v n Like -a, omitting output for paired lines.
-e s Replace empty output fields by string s.
-1 m
-2 m Join on the mth field of file1 or file2.
-jn m Archaic equivalent for -n m.
-ofields
Each output line comprises the designated fields. The comma-separated field designators are either 0, meaning the join field, or
have the form n.m, where n is a file number and m is a field number. Archaic usage allows separate arguments for field designators.
-tc Use character c as the only separator (tab character) on input and output. Every appearance of c in a line is significant.
EXAMPLES
sort /etc/passwd | join -t: -1 1 -a 1 -e "" - bdays
Add birthdays to the /etc/passwd file, leaving unknown birthdays empty. The layout of /adm/users is given in passwd(5); bdays con-
tains sorted lines like
tr : ' ' </etc/passwd | sort -k 3 3 >temp
join -1 3 -2 3 -o 1.1,2.1 temp temp | awk '$1 < $2'
Print all pairs of users with identical userids.
SOURCE
/src/cmd/join.c
SEE ALSO sort(1), comm(1), awk(1)BUGS
With default field separation, the collating sequence is that of sort -b -ky,y; with -t, the sequence is that of sort -tx -ky,y.
One of the files must be randomly accessible.
JOIN(1)