What is the 'awk' for? That doesn't look like awk code. (awk is its own programming language.)
You do not need to check if grep's output is blank to see if it found anything. It returns a success or failure code like any other utility. You can plug it into if directly, and invert with ! if needed.
'break' only makes sense in a loop. If you want to exit, 'exit' is what you want, 'exit 1' to exit with error particularly.
Your code looks for /temp, but your warning demands /tmp. Assuming /tmp is what you really want.
You need a return, or ; , between your if statement and the then.
I'm creating an oracle insert statement using awk but need to be able to escape the ' (forward single quote) as the oralce insert syntax requires these quotes. I've tried \ in and out of quotes etc.
It's these single quotes values (' .....')
cat $1 | awk -F"|" '{print "insert into table... (2 Replies)
her i am trying to edit a database file which is actually a small file holding my friend's name and birthdays
My Database
DEEPAK 27/08
DEEPIKA 18/02
DHYAN 23/03
DIPANKAR 24/10
SNIGDHO 19/05
AYANNAR 17/12
BHAI 22/09
DEBAN 16/08
JAGADISH 02/06
SUBHOJIT 23/02
TOJO 17/09
SUDHIR 12/09... (1 Reply)
Hey, I'm running knoppix and I'm trying to run a shell script to change multiple lines of text in multiple files
#!/bin/sh
for i in 'ls-1 test'
do
sed 's/bob/manny/'g $i > $i.0
mv $i.0 $i
done
Obviously this isn't the original file, but it's on another non-networked machine.
What... (7 Replies)
Hi guys, I am a newbie to shell scripting.Please help me to accomplish this task. Its very urgent,I should create a script which will do the following:
i) "cd ~joseph/ ; mkdir -p Bing/Bong ;mkdir -p Bing/Bang" and then create 15 ".txt" files with content "Bing Bang Bong" in "Bong"... (1 Reply)
Hi,
#!/bin/ksh
$v=""
for ((i = 1 ; i <= 5 ; i++ ))
do
v="THerrFile_$i.err";
grep -i "$i:Error" $v >>oraerror_output.txt
done
My requirement is to dynamically create variable like
THerrFile_1.err,THerrFile_2.err etc.
where my grep needs... (5 Replies)
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
Hello all,,, I am trying to finish my assignment for my CNET class. I am running into 2 problems... First the "Delete a file" (Option 1) When I run this option everything... (5 Replies)
I am trying to create a shell script similar to ls, but which only lists directories. I have the first half working (no argument version), but trying to make it accept an argument, I am failing. My logic is sound I think, but I'm missing something on the syntax, I'm guessing in the bolded line? ... (9 Replies)
Hi,
I wants to print the 9th column information with its path name in some txt file. Here is one line which works fine for me:
rfdir /castor/cern.ch/user/s/sudha/forPooja | grep data | awk '{print "rfio:///castor/cern.ch/user/s/sudha/forPooja/"$9}' > dataFilenames.list
rfdir=="ls -ltr" ... (2 Replies)
Hello all,
I am facing a weird issue while executing a code below -
#!/bin/bash
cd /wload/baot/home/baotasa0/sandboxes_finance/ext_ukba_bde/pset
sh UKBA_publish.sh UKBA 28082015 3
if
then
echo "Param file conversion for all the areas are completed, please check in your home directory"... (2 Replies)
Hello. I hava homework for university but i cant do it and i need a little help if someone can help me :) I have to do a linux shell script.
Write a script that does the following:
1. Check if there is a directory in / home with myDir name.
If not, it creates it.
2. In the directory it... (1 Reply)
Discussion started by: alex4o0o
1 Replies
LEARN ABOUT X11R4
flock
FLOCK(1) User Commands FLOCK(1)NAME
flock - manage locks from shell scripts
SYNOPSIS
flock [options] file|directory command [arguments]
flock [options] file|directory -c command
flock [options] number
DESCRIPTION
This utility manages flock(2) locks from within shell scripts or from the command line.
The first and second of the above forms wrap the lock around the execution of a command, in a manner similar to su(1) or newgrp(1). They
lock a specified file or directory, which is created (assuming appropriate permissions) if it does not already exist. By default, if the
lock cannot be immediately acquired, flock waits until the lock is available.
The third form uses an open file by its file descriptor number. See the examples below for how that can be used.
OPTIONS -c, --command command
Pass a single command, without arguments, to the shell with -c.
-E, --conflict-exit-code number
The exit code used when the -n option is in use, and the conflicting lock exists, or the -w option is in use, and the timeout is
reached. The default value is 1.
-F, --no-fork
Do not fork before executing command. Upon execution the flock process is replaced by command which continues to hold the lock.
This option is incompatible with --close as there would otherwise be nothing left to hold the lock.
-e, -x, --exclusive
Obtain an exclusive lock, sometimes called a write lock. This is the default.
-n, --nb, --nonblock
Fail rather than wait if the lock cannot be immediately acquired. See the -E option for the exit code used.
-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 holding the lock.
-s, --shared
Obtain a shared lock, sometimes called a read lock.
-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.
-w, --wait, --timeout seconds
Fail if the lock cannot be acquired within seconds. Decimal fractional values are allowed. See the -E option for the exit code
used. The zero number of seconds is interpreted as --nonblock.
--verbose
Report how long it took to acquire the lock, or why the lock could not be obtained.
-V, --version
Display version information and exit.
-h, --help
Display help text and exit.
EXAMPLES
shell1> flock /tmp -c cat
shell2> flock -w .007 /tmp -c echo; /bin/echo $?
Set exclusive lock to directory /tmp and the second command will fail.
shell1> flock -s /tmp -c cat
shell2> flock -s -w .007 /tmp -c echo; /bin/echo $?
Set shared lock to directory /tmp and the second command will not fail. Notice that attempting to get exclusive lock with second
command would fail.
shell> flock -x local-lock-file echo 'a b c'
Grab the exclusive lock "local-lock-file" before running echo with 'a b c'.
(
flock -n 9 || exit 1
# ... commands executed under lock ...
) 9>/var/lock/mylockfile
The form is convenient inside shell scripts. The mode used to open the file doesn't matter to flock; using > or >> allows the lock-
file to be created if it does not already exist, however, write permission is required. Using < requires that the file already
exists but only read permission is required.
[ "${FLOCKER}" != "$0" ] && exec env FLOCKER="$0" flock -en "$0" "$0" "$@" || :
This is useful boilerplate code for shell scripts. Put it at the top of the shell script you want to lock and it'll automatically
lock itself on the first run. If the env var $FLOCKER is not set to the shell script that is being run, then execute flock and grab
an exclusive non-blocking lock (using the script itself as the lock file) before re-execing itself with the right arguments. It
also sets the FLOCKER env var to the right value so it doesn't run again.
EXIT STATUS
The command uses sysexits.h return values for everything, except when using either of the options -n or -w which report a failure to
acquire the lock with a return value given by the -E option, or 1 by default.
When using the command variant, and executing the child worked, then the exit status is that of the child command.
AUTHOR
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 package and is available from Linux Kernel Archive <https://www.kernel.org/pub/linux/utils
/util-linux/>.
util-linux July 2014 FLOCK(1)