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Old 05-19-2005, 11:58 AM   #1
schneidz
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Registered: May 2005
Location: boston, usa
Distribution: fc-15/ fc-20-live-usb/ aix
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Question weird sed output


i am getting this weird output from sed. i am expecting it to only print out line 5:
gouki

but it is printing everything with line 5 duplicated. here is the example with system info:

schneidz@lq> uname -a -M -p
AIX lq 2 5 00yyyyyy4C00 powerpc IBM,7040-671
schneidz@lq> cat lq.txt
hello
world
l33t
h4x0r
gouki
chun-li
schneidz@lq> sed 5p lq.txt
hello
world
l33t
h4x0r
gouki
gouki
chun-li


let me know what you find out?
thanx
schneidz
 
Old 05-19-2005, 12:03 PM   #2
rose_bud4201
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Registered: Aug 2002
Location: St Louis, MO
Distribution: Xubuntu, RHEL, Solaris 10
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This appears to be a known issue.
From http://www.linuxselfhelp.com/gnu/sed...ter/sed_3.html:

Quote:
`p'
Print out the pattern space (to the standard output). This command is usually only used in conjunction with the -n command-line option. Note: some implementations of SED, such as this one, will double-print lines when auto-print is not disabled and the p command is given. Other implementations will only print the line once. Both ways conform with the POSIX.2 standard, and so neither way can be considered to be in error. Portable SED scripts should thus avoid relying on either behavior; either use the -n option and explicitly print what you want, or avoid use of the p command (and also the p flag to the s command).
Therefore,
Code:
me@localhost:~$ sed 5p lq.txt
hello
world
l33t
h4x0r
gouki
gouki
gouki
chun-li
me@localhost:~$ sed -n 5p lq.txt
gouki
HTH!
 
Old 05-19-2005, 12:08 PM   #3
schneidz
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thx rosebud (not sure if that is a citizen kane or h2g2 reference).

works for me too.
 
Old 05-19-2005, 12:16 PM   #4
rose_bud4201
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heh...unfortunately neither- I'd feel a lot less silly if it were a nice explainable reference.
Sadly it's just a carryover from an old email address that I used when I was in high school, and I'm just sort of used to typing it.

*shrug*
 
  


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