6 More Discussions You Might Find Interesting
1. UNIX for Beginners Questions & Answers
Hello,
I am on a Mac and trying to clean up some monthly files with a very simple SED:
sed '3,10d;/<ACROSS>/,$d' input.txt > output.txt
(from the input, delete lines 3 - 10; then delete from the line containing <ACROSS> to the end of the file)
then output to output.txt
Even when I try... (2 Replies)
Discussion started by: verbatim
2 Replies
2. UNIX for Beginners Questions & Answers
Now I'm trying summary sar data.
CPU , Memory , Traffic , TPS (Min Max value)
CPU is okay using below command.
$ sar -p | awk '{gsub(//,"")}1' | awk 'BEGIN {min=1000000; max=0;};\
{ if($7<min && $7 != "") min = $7; if($7>max && $7 != "") max = $7; } END {print min, max}'
98.93 99.55
... (1 Reply)
Discussion started by: tom8254
1 Replies
3. Red Hat
Hi,
Can anyone help me on migration the print server from AIX to RHEL 4?
Appreciate your help? (1 Reply)
Discussion started by: brby07
1 Replies
4. Red Hat
helo
i want to show today date and calendar when v succesfuly login on the system on the linux server
please orovide the sol for the same
thanx :):):) (1 Reply)
Discussion started by: dodasajan
1 Replies
5. UNIX for Dummies Questions & Answers
It my first post here .
I just want to get the content of the file as values for printinting along with line number in LINUX
Here is what I tried .
$ cat test1.txt
ABC
DSF
GHI
JKL
MNO
PQR
STU
VWX
YZO
$ cat test.sh
#!/bin/ksh (4 Replies)
Discussion started by: rajavu
4 Replies
6. UNIX for Dummies Questions & Answers
Hi All,
Perhaps a dumb question, but how do you do a "print screen" within the X-Window in linux. I'm running KDE, is there a utility I can use in that package that I'm not aware of. Or, is there a way to turn on the <alt><print-screen> function with the keyboard?
Thanks in advance.
VJ (2 Replies)
Discussion started by: vancouver_joe
2 Replies
FLOCK(1) H. Peter Anvin FLOCK(1)
NAME
flock - Manage locks from shell scripts
SYNOPSIS
flock [-sxon] [-w timeout] lockfile [-c] command...
flock [-sxon] [-w timeout] lockdir [-c] command...
flock [-sxun] [-w timeout] fd
DESCRIPTION
This utility manages flock(2) locks from within shell scripts or the command line.
The first and second forms wraps the lock around the executing a command, in a manner similar to su(1) or newgrp(1). It locks a specified
file or directory, which is created (assuming appropriate permissions), if it does not already exist.
The third form is convenient inside shell scripts, and is usually used the following manner:
(
flock -s 200
# ... commands executed under lock ...
) 200>/var/lock/mylockfile
The mode used to open the file doesn't matter to flock; using > or >> allows the lockfile to be created if it does not already exist, how-
ever, write permission is required; using < requires that the file already exists but only read permission is required.
By default, if the lock cannot be immediately acquired, flock waits until the lock is available.
OPTIONS
-s, --shared
Obtain a shared lock, sometimes called a read lock.
-x, -e, --exclusive
Obtain an exclusive lock, sometimes called a write lock. This is the default.
-u, --unlock
Drop a lock. This is usually not required, since a lock is automatically dropped when the file is closed. However, it may be
required in special cases, for example if the enclosed command group may have forked a background process which should not be hold-
ing the lock.
-n, --nb, --nonblock
Fail (with an exit code of 1) rather than wait if the lock cannot be immediately acquired.
-w, --wait, --timeout seconds
Fail (with an exit code of 1) if the lock cannot be acquired within seconds seconds. Decimal fractional values are allowed.
-o, --close
Close the file descriptor on which the lock is held before executing command. This is useful if command spawns a child process
which should not be hold ing the lock.
-c, --command command
Pass a single command to the shell with -c.
-h, --help
Print a help message.
AUTHOR
Written by H. Peter Anvin <hpa@zytor.com>.
COPYRIGHT
Copyright (C) 2003-2006 H. Peter Anvin.
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICU-
LAR PURPOSE.
SEE ALSO
flock(2)
AVAILABILITY
The flock command is part of the util-linux-ng package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.
flock utility 4 Feb 2006 FLOCK(1)