If it's something you only do once, it t really belong in a function you call 10,000 times. Do it before the loop.
This is especially true since the value of `date` may change if your script takes a long time to finish! Even if it doesn't, you're running date 10,000 times when all you needed was to run it once. Save it into a variable.
What is this if [ $2 ] ? I suspect that doesn't do what you think it does.
Another question, is it possible to, in a for-loop incrementing until it reaches a certain number, to have it loop again without incrementing? Just have it drop what it is doing when it reaches this command and start again at the same number it was at? I know I could make a while loop and just... (0 Replies)
Hi All,
I amlearning UNIX scripting. I have a small query. I would be thankful if any one helps me out.
I have a below piece of code which delets the files. If file dosent have the permissions to delete a particular file I have used 2>>operator to track the error code.
But my objective is... (1 Reply)
I wonder how to stop further loop iterations when conditions gets false e.g.
This file.txt contains the following structure :
1
2
3
4
5
6
7
8
9
10
How to stop iteration when if statement gets false ?
for n in `cat file.txt`
do
if (( n<=5 )) (1 Reply)
question :how can i iterate to next item in for loop with the loop
e.g
for i in `cat abc.txt`
do
echo $i // this will display first line
i=$i+1; // this doesnt work for me.
echo $i; //this will display secound line
done
question: is my approach to manipulate text good?
I have... (3 Replies)
I have written the following script to update some Debian boxes.
#!/bin/bash
mxg_hosts_file="/etc/mxg/ssh-hosts"
while read line ; do
mxg_host="$(echo ${line} | awk -F":" '{print $1}')"
mxg_port="$(echo ${line} | awk -F":" '{print $2}')"
echo "Connecting and Upgrading... (3 Replies)
for VGLIST in `lsvg -o`
do
CLOSED_OUT=`echo $VGLIST | lsvg -l $VGLIST | awk '{print $6 " " $7}' | grep closed`
if ]; then
echo "Filesystems $CLOSED_OUT in VG that are in Closed status"
else
echo "\n Some message"
fi
Above Code is working fine, but echo "Filesystems $CLOSED_OUT... (8 Replies)
bash in RHEL 6.4
I have a requirement in which I want to get the iteration count from a WHILE LOOP.
The below mentioned simple script test.sh works fine. In the below script, the WHILE loop will iterate every 5 seconds infinitely until it greps the string BASKETBALL from /tmp/somestring.txt... (6 Replies)
I am trying to check multiple server's "uptime" in a loop over "ssh".
When I execute multiple ssh commands with hard coded servernames script is executing fine.
But when I pass server names using while loop, script is exiting after checking first server's status, why?
# serverList... (8 Replies)
Hello,
I have been stuck on this for some time and invested many hours trying to find a solution. I am trying to either loop through two variables or or two arrays and not sure how to do it. I am limited to ksh only, and don't have the ability to do a foreach, or for i AND for j etc...I... (19 Replies)
Hello,
I've written a script to automate encoding of all the MP4 files in a directory (incl. subdirectories). But unfortunately it's running for the first MP4 file only.
My machine details:
root@Ubuntu16:~# uname -a
Linux Ubuntu16 4.10.0-28-generic #32~16.04.2-Ubuntu SMP Thu Jul 20 10:19:48... (2 Replies)
Discussion started by: prvnrk
2 Replies
LEARN ABOUT BSD
date
DATE(1) General Commands Manual DATE(1)NAME
date - print and set the date
SYNOPSIS
date [-nu] [-d dst] [-t timezone] [yymmddhhmm [.ss] ]
DESCRIPTION
If no arguments are given, the current date and time are printed. Providing an argument will set the desired date; only the superuser can
set the date. The -d and -t flags set the kernel's values for daylight savings time and minutes west of GMT. If dst is non-zero, future
calls to gettimeofday(2) will return a non-zero tz_dsttime. Timezone provides the number of minutes returned by future calls to gettimeof-
day(2) in tz_minuteswest. The -u flag is used to display or set the date in GMT (universal) time. yy represents the last two digits of
the year; the first mm is the month number; dd is the day number; hh is the hour number (24 hour system); the second mm is the minute num-
ber; .ss is optional and represents the seconds. For example:
date 8506131627
sets the date to June 13 1985, 4:27 PM. The year, month and day may be omitted; the default values will be the current ones. The system
operates in GMT. Date takes care of the conversion to and from local standard and daylight-saving time.
If timed(8) is running to synchronize the clocks of machines in a local area network, date sets the time globally on all those machines
unless the -n option is given.
FILES
/usr/adm/wtmp to record time-setting. In /usr/adm/messages, date records the name of the user setting the time.
SEE ALSO gettimeofday(2), utmp(5), timed(8),
TSP: The Time Synchronization Protocol for UNIX 4.3BSD, R. Gusella and S. Zatti
DIAGNOSTICS
Exit status is 0 on success, 1 on complete failure to set the date, and 2 on successfully setting the local date but failing globally.
Occasionally, when timed synchronizes the time on many hosts, the setting of a new time value may require more than a few seconds. On
these occasions, date prints: `Network time being set'. The message `Communication error with timed' occurs when the communication between
date and timed fails.
BUGS
The system attempts to keep the date in a format closely compatible with VMS. VMS, however, uses local time (rather than GMT) and does not
understand daylight-saving time. Thus, if you use both UNIX and VMS, VMS will be running on GMT.
4th Berkeley Distribution March 24, 1987 DATE(1)