Command to sort 3 letters month in AIX - sorting

Have a file containing values :
Sep 17 11:07 2016
Jan 03 20:33 2018
Apr 14 11:53 2015
Dec 28 07:28 2017
Aug 10 11:55 2011
Dec 25 17:53 2017
Have sort -M option in other flavors of UNIX OS. But no luck in AIX.
Please help in sorting 3 letter month. Thanks in advance.!

Related

How to perform date operations in bash

Basically, I want to take a time, and day of the week, in UTC+8, and adjust the datetime object to a given UTC offset, within bash, I don't have any code to show because I'm not sure how to start attempting this in the first place honestly
(I'm writing a custom script for a friend who lives in UTC+8 and want to make the input as easy as possible for them, basically they just give it a time in their timezone, and a day of the week, and it'll tell them what date and time that'll be in a different timezone, for an overarching purpose)
For a reference, look at the section 1 of the manual page for "date":
In your shell, just type: man 1 date
or see the online man page:
https://man7.org/linux/man-pages/man1/date.1.html
One way is to parse the date into the number of seconds since epoch (since 1970), and then convert that number of seconds into the format you want:
For example:
$ date +%s --date='2022-12-27 11:30:17 +008'
1672140137
$ date +%c --date='#1672140137'
Tue 27 Dec 2022 06:22:17 AM EST
or you could also convert to ISO format then back to local time
$ date -Iseconds --date='TZ="GMT" 2022-12-22 11:33:44 +08'
2022-12-21T22:33:44-05:00
$ date --date='2022-12-21T22:33:44-05:00'
Wed 21 Dec 2022 10:33:44 PM EST
I hope this helps you get started with some ideas for converting to/from different timezones.
Also, to help with user input, you can show the current month calendar using cal
$ cal
December 2022
Su Mo Tu We Th Fr Sa
1 2 3
4 5 6 7 8 9 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30 31
$ date --date='Fri 08:30'
Fri 30 Dec 2022 08:30:00 AM EST
In the above example, I specified "Fri 08:30" which gets set to the next Friday at 08:30 in the morning for my local timezone.

Printing end-of-line field in awk causing formatting issues

I have a log file that contains output from
/bin/df -h| /usr/bin/grep p_log|/usr/bin/awk -v date="$(date)" '{print date,$4,$5}'
which is later sent out using mailx. It arrives in my PC's Outlook as desired with a line per entry and displays with a line end in cat -A:
Wed Mar 16 10:29:01 EDT 2022 291G 95%$
Wed Mar 16 11:29:01 EDT 2022 290G 95%$
Wed Mar 16 12:29:02 EDT 2022 290G 95%$
Adding an additional field to the awk - $6 happens to be the last field in the df output - still displays the same with cat:
Wed Mar 16 11:29:01 EDT 2022 290G 95%$
Wed Mar 16 12:29:02 EDT 2022 290G 95%$
Wed Mar 16 13:29:01 EDT 2022 290G 95% /.p_log$
Wed Mar 16 14:29:02 EDT 2022 290G 95% /.p_log$
But lines are now concatenated when read in Windows/Outlook:
Wed Mar 16 10:29:01 EDT 2022 291G 95%
Wed Mar 16 11:29:01 EDT 2022 290G 95%
Wed Mar 16 12:29:02 EDT 2022 290G 95%
Wed Mar 16 13:29:01 EDT 2022 290G 95% /.p_log Wed Mar 16 14:29:02 EDT 2022 290G 95% /.p_log
I found another post at explains that cat -e (which I have tried, and is encompassed by -A) "displays Unix line endings (\n or LF) as $ and Windows line endings (\r\n or CRLF) as ^M$". Why then are two lines that display the same control characters in cat being displayed differently in Windows/how best to get the line feed back when printing $6 without messing up the formatting of the log? I presume there are more hidden control characters that cat -A does not display, i.e. that 'all' does not actually mean all.
Further testing: There are header and footer lines - all ending in the same "$"- that do not get concatenated. I tried attaching the content from the end of one of the concatenated lines to a header line and that would indicate that it's the "/" that's causing the problem, but only for mailx.
Looks like I've been barking up the wrong tree; not sure if I should delete this question and open a new one for mailx?
Adding two spaces to the start of each line - https://stackoverflow.com/a/22098987/8823709 - resolved the issue. I don't know why, but it did.

bash variable doubles in value - why?

I have a simple shell script set up to capture images every X seconds. For some reason the value of X seems to double each time through the loop.
#!/bin/bash
# basic setup for time-lapse
SECONDS=1
while true
do
DATE=$(date +"%Y-%m-%d_%H%M%S")
filename=${DATE}_img.jpg
# fswebcam -r 1280x720 --timestamp "%a %Y-%b-%d %H:%M (%Z)" /home/pi/JPGS/$filename
date
echo "pausing for ${SECONDS} seconds"
sleep $SECONDS
date
echo "====="
done
This is the output I get. The value of SECONDS is not manipulated inside the loop, so I'm confused with what is happening here. Also, the original interval was 30 seconds, I changed it to 1 seconds for testing purposes, and the date calls are for testing/debugging too.
Sun Mar 3 17:51:57 CST 2019
pausing for 1 seconds
Sun Mar 3 17:51:58 CST 2019
=====
Sun Mar 3 17:51:58 CST 2019
pausing for 2 seconds
Sun Mar 3 17:52:00 CST 2019
=====
Sun Mar 3 17:52:00 CST 2019
pausing for 4 seconds
Sun Mar 3 17:52:04 CST 2019
=====
Sun Mar 3 17:52:04 CST 2019
pausing for 8 seconds
Sun Mar 3 17:52:12 CST 2019
=====
Sun Mar 3 17:52:12 CST 2019
pausing for 16 seconds
Sun Mar 3 17:52:28 CST 2019
=====
Sun Mar 3 17:52:28 CST 2019
pausing for 32 seconds
Sun Mar 3 17:53:00 CST 2019
=====
Sun Mar 3 17:53:00 CST 2019
pausing for 64 seconds
Sun Mar 3 17:54:04 CST 2019
=====
Sun Mar 3 17:54:04 CST 2019
pausing for 128 seconds
What am I missing here?
This is under a Raspberry Pi
Pick a different name for $SECONDS.
$SECONDS is a built-in shell variable. It expands to the number of seconds since the shell was started.
From the Bash manual:
'SECONDS'
This variable expands to the number of seconds since the shell was
started. Assignment to this variable resets the count to the value
assigned, and the expanded value becomes the value assigned plus the
number of seconds since the assignment.
$SECONDS is actually a special Bash Variable for timing the number of seconds a script has been running. Because it's a timer, it increments automatically every second without the script doing anything. Just change the variable name to something else and you should be fine.

What does [143x40] mean in the output of tmux list-sessions?

I have 4 tmux sessions present. When I use
tmux list-sessions
It shows the sessions with some numbers in the brackets. That is:
t128_1: 1 windows (created Thu Jul 19 12:20:44 2018) [71x38]
t128_2: 1 windows (created Thu Jul 19 12:20:54 2018) [71x38]
t3: 1 windows (created Thu Jul 19 12:19:59 2018) [143x40]
t6: 1 windows (created Thu Jul 19 12:20:27 2018) [71x38]
What does the number [AxB] mean? And why t3 session has a different value than the others? Thanks for any explanation.
That's the size of the terminal (143 columns, 40 rows) the last time a client attached to the session.

How to remove the static message that appears when opening a Linux shell?

How to remove the following message:
To run a command as administrator (user "root"), use "sudo ".
See "man sudo_root" for details.
Every time I open a Terminal it appears. I upgraded from Ubuntu 14.04 LTS to 16.04 LTS and it seems that update made that.
I am using bash.
I googled that and found this command:
$ touch ~/.hushlogin
Execute the below command and close the terminal. The message will be remove from the terminal.
sudo apt-get update
atleast my ubuntu 14.04 machine will display(or run) all the script in /etc/update-motd.d(motd => message of the day) directory.
ll /etc/update-motd.d/
total 40
drwxr-xr-x 2 root root 4096 Sep 27 2014 ./
drwxr-xr-x 109 root root 4096 Nov 30 10:27 ../
-rwxr-xr-x 1 root root 1220 Feb 20 2014 00-header*
-rwxr-xr-x 1 root root 1358 Feb 20 2014 10-help-text*
lrwxrwxrwx 1 root root 46 Sep 27 2014 50-landscape-sysinfo -> /usr/share/landscape/landscape-sysinfo.wrapper*
-rwxr-xr-x 1 root root 334 Sep 27 2014 51-cloudguest*
-rwxr-xr-x 1 root root 149 Aug 22 2011 90-updates-available*
-rwxr-xr-x 1 root root 299 Aug 21 2014 91-release-upgrade*
-rwxr-xr-x 1 root root 111 Mar 27 2014 97-overlayroot*
-rwxr-xr-x 1 root root 142 Aug 22 2011 98-fsck-at-reboot*
-rwxr-xr-x 1 root root 144 Aug 22 2011 98-reboot-required*
The scipt with lowest number is gonna execute first 00-header*

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