hi all. i have a little problem. im basically reading input from the user from the keyboard into the variable "phonenumber". I want to do a little error check to check if the user doesnt enter anything in for the value phonenumber.
i had this:
read phonenumber
if
then
.....
else
........ (2 Replies)
Hi everyone - I am sure this is a really simple problem but I'm a total noob at Linux scripting:
I wanted to create a script that allows me to compare the current week number to the contents of a text file in my home directory:
VAR1='date +%V'
VAR2='cat /home/fred/file.txt'
... (6 Replies)
Hi
New to shell script and awk and need assistance on this problem. I need to use a variable to substitute a string in an external file and write the changed info to another file.
At first I did not know if you could use a variable as the sub value but the following showed me that I can.
... (3 Replies)
Hello;
Trying to figure out how to keep just the contents between the two search lines:
awk '/regexp_1/ ,/regexp_2/'
I do not want lines containing regexp_1 and regexp_2 in the output.
Thank you for any ideas
Video tutorial on how to use code tags in The UNIX and Linux Forums. (5 Replies)
Hello;
I need to print two previous lines after searching for a reg exp:
awk '/haywood/'
should produce the following
===================
p9J46THe020804 89922 Tue Oct 18 21:06 MAILER-DAEMON
(host map: lookup (haywood.com): deferred)
... (1 Reply)
Hello;
we have :
awk '/reg_exp/,0/
prints every line after the first occurrence of "reg_exp"
But if I want to print rest of the lines AFTER the last occurrence of "reg_exp",
how would I do it ??
Tried :
awk ' ! (/reg_exp/,0)'
But it errored...
Thank you for any... (5 Replies)
Discussion started by: delphys
5 Replies
LEARN ABOUT FREEBSD
sleep
SLEEP(1) BSD General Commands Manual SLEEP(1)NAME
sleep -- suspend execution for an interval of time
SYNOPSIS
sleep seconds
DESCRIPTION
The sleep command suspends execution for a minimum of seconds.
If the sleep command receives a signal, it takes the standard action. When the SIGINFO signal is received, the estimate of the amount of
seconds left to sleep is printed on the standard output.
IMPLEMENTATION NOTES
The SIGALRM signal is not handled specially by this implementation.
The sleep command allows and honors a non-integer number of seconds to sleep in any form acceptable by strtod(3). This is a non-portable
extension, and its use will nearly guarantee that a shell script will not execute properly on another system.
EXIT STATUS
The sleep utility exits 0 on success, and >0 if an error occurs.
EXAMPLES
To schedule the execution of a command for x number seconds later (with csh(1)):
(sleep 1800; sh command_file >& errors)&
This incantation would wait a half hour before running the script command_file. (See the at(1) utility.)
To reiteratively run a command (with the csh(1)):
while (1)
if (! -r zzz.rawdata) then
sleep 300
else
foreach i (`ls *.rawdata`)
sleep 70
awk -f collapse_data $i >> results
end
break
endif
end
The scenario for a script such as this might be: a program currently running is taking longer than expected to process a series of files, and
it would be nice to have another program start processing the files created by the first program as soon as it is finished (when zzz.rawdata
is created). The script checks every five minutes for the file zzz.rawdata, when the file is found, then another portion processing is done
courteously by sleeping for 70 seconds in between each awk job.
SEE ALSO nanosleep(2), sleep(3)STANDARDS
The sleep command is expected to be IEEE Std 1003.2 (``POSIX.2'') compatible.
HISTORY
A sleep command appeared in Version 4 AT&T UNIX.
BSD April 18, 1994 BSD