I am new to bash and shell but I am running a debian install and I am trying to make a script which can find a date in the past without having to install any additional packages. From tutorials I have got to this stage:
#!/bin/sh
#
# BACKUP DB TO S3
#
# VARIABLES
TYPE="DATABASE"
DAYS="30"
# GET CURRENT DATETIME
CURRENTDATE="$(date +%Y%m%d%H%M%S)"
# GENERATE PAST DATE FROM DAYS CONTSTANT
OLDERDATE=`expr $CURRENTDATE - $DAYS'
# CALL PYTHON SCRIPT WITH OLDERDATE ARGUMENT
python script.py $OLDERDATE
Where I am getting stuck is the fact that my "days" is just the number 30 and isnt datetime formattted, so when I come to minus it from the currentdate variable it obviously isnt compatible.
Would anyone be kind enough to help me find a way to get this working as it should?
Try
date -d '30 days ago'
should do on debian.
Try doing this :
#!/bin/sh
#
# BACKUP DB TO S3
#
# VARIABLES
TYPE="DATABASE"
DAYS="30"
# GET CURRENT DATETIME
CURRENTDATE="$(date +%Y%m%d%H%M%S)"
# GENERATE PAST DATE FROM DAYS CONSTANT
OLDERDATE="$(date "+%Y%m%d%H%M%S" -d "$DAYS days ago")"
# CALL PYTHON SCRIPT WITH OLDERDATE ARGUMENT
python script.py "$OLDERDATE"
See info coreutils 'date invocation' | less +/28.7\ Relative\ items\ in\ date\ strings
You can use the following script:
#!/bin/bash
days=73
while [ ${days} -ge 0 ]; do
date -d "${days} days ago" +'%F'
days=$((days-1))
done
You could modify the python script instead -- that way you would not depend on particular implementation of date
Related
Here is my issue: I have a backup bash script that needs to access a folder with a date in its name for example : backup_01072022 .
I used date=`TZ=GMT+24 date +%d%m%Y` when i needed to access the backup folder of yesterday.
Now I want to access the backup folder of last week :
date=`TZ=GMT+168 date +%d%m%Y` , it doesn't work , it show today's date.
I read that TZ doesn't work for a value above +144.
Is there any other way of manipulating dates in SunOS 6.8 ?
Notes :
SunOS 6.8
version of the date util : 8.5
version of bash : 4.1.11(2)-release
This'll depend on the version of date on your system.
With GNU date (v 8.26):
$ TZ=GMT date '+%d%m%Y'
06072022 # today
$ TZ=GMT date '+%d%m%Y' -d 'last week'
29062022
$ TZ=GMT date '+%d%m%Y' -d '7 days ago'
29062022
NOTE: I'll leave it up to OP to determine if the explicit TZ setting should be adjusted (or used at all)
I seem to recall SunOS comes with Perl, so if you don't have a date that supports --date="...", you should be able to do:
date=$(perl -MPOSIX -e '
print POSIX::strftime "%d%m%Y", localtime time-(60*60*24*7)
')
Thanks to the helpful commments and answers I was able to make it work using :
/usr/gnu/bin/date -d "last week" '+%d%m%Y'
It turns out I was not using the GNU date util until I specified it explicitly, and that's neither --date nor -d was working for me.
I still can't figure out what date util I was using by default if not GNU date.
I m trying to get yesterday date, it's not working in hp ux server.
Prev_date=$(date +"y%m%d" -d "1 day ago")
For this I m still getting current date only.
20210811
Could you please help on the same.
You missed a percentage in front of the 'y': this is working fine for me:
echo $(date +"%y%m%d" -d "1 day ago")
You can use below command, if you want.
date --date=' 1 days ago' '+%Y-%m-%d'
It will give result like
2021-09-06
I prefer this format since most of the time my scripts include SQL queries for data fetch and hence date is required to filter out data on daily basis.
I'm working on a ksh script to retrieve a file every hour via sftp that will be put on a job scheduler to be run hourly. The script must navigate to a folder with yesterday's date (remote/path/yyyymmdd/). The filename also has yesterday's date and a timestamp (filename_yyyymmdd_hhmmss.dat). Since the job will be scheduled, my script has to include the previous hour - ex. if the job runs at 11:02, the file to retrieve would be filename_yyyymmdd_10mmss.dat. The minutes and seconds will always be the same - ex 4949. There will be multiple files in the remote directory and I only want to retrieve the latest one so that there are not multiple input files being processed by our jobs. The remote directory will also have other files being created regularly, so I can't retrieve just the last modified files.
I have variables to return yesterday's date and the previous hour, but the sftp command isn't returning the full filename and isn't retrieving the file. I've tried concatenating the variables, using brackets & quotes & parenthesis, assigning multiple variables to a single variable, and exporting the variables.
vdate=$(TZ=bb24 date '+%Y%m%d')
vhour=$(date '+%H')
prevhour=$((vhour - 1))
sftp user#host << EOF
lcd /my/dir/
cd /remote/path/$vdate/
get filename_$vdate_$prevhour*.dat
bye
EOF
exit
When running the script, the file cannot be found and the full filename isn't
returned:
File "/remote/path/20190411/filename_20190411" not found.
instead of
File "/remote/path/20190411/filename_20190411_10*.dat" not found.
Every combination of variables that I try returns the same not found - ending after filename_$vdate.
I've tried some other combinations but always get the same not found:
newvar=${vdate}_${prevhour}
get filename_$newvar*.dat
and
newvar=${vdate}\\_${prevhour}
get filename_$newvar*.dat
File "/remote/path/20190411/filename_20190411" not found.
You have a problem in your script at prevhour=$((vhour - 1))
this way a text 02 after you make subtraction, it will be 1 and not 01 and it will match to undesired files, or even none as 00 - 1 is -1
[edvin]$ vdate=$(TZ=bb24 date '+%Y%m%d')
[edvin]$ vhour=$(date '+%H')
[edvin]$ prevhour=$((vhour - 1))
[edvin]$ echo $vhour
03
[edvin]$ echo $prevhour
2
[edvin]$ prevhour=$(date -d '1 hour ago' '+%H')
[edvin]$ echo $prevhour
02
date's -d option not avaliable on some system.
I believe in that in your attempt the shell is considered the * as part of the variable prevhour as you did not put it into {} that separate variables from sorrunding text.
This is my working solution based by your attempt:
#!/bin/ksh
r_host='server2'
r_user='edvin'
l_dir='./content'
r_dir='./Test_folder'
# this still not cover the case of midnight
# it put 00 to 23 but day have to be yesterday as well
##vdate=$(TZ=bb24 date '+%Y%m%d')
##vhour=$(date '+%H') # not used
##prevhour=$(date -d '1 hour ago' '+%H')
# vtime = YYYYmmdd_HH -1 H
vtime=$(TZ=bb24 date -d '1 hour ago' '+%Y%m%d_%H')
sftp ${r_user}#${r_host} << EOF
lcd ${l_dir}
cd ${r_dir}
get filename_${vtime}*.dat
bye
EOF
exit
Output:
[edvin]$ ./script.ksh
Connected to server2.
sftp> lcd ./content
sftp> cd ./Test_folder
sftp> get filename_20190415_02*.dat
Fetching /home/edvin/Test_folder/filename_20190415_020000.dat to filename_20190415_020000.dat
Fetching /home/edvin/Test_folder/filename_20190415_020100.dat to filename_20190415_020100.dat
Fetching /home/edvin/Test_folder/filename_20190415_020200.dat to filename_20190415_020200.dat
Fetching /home/edvin/Test_folder/filename_20190415_020300.dat to filename_20190415_020300.dat
Fetching /home/edvin/Test_folder/filename_20190415_020400.dat to filename_20190415_020400.dat
Fetching /home/edvin/Test_folder/filename_20190415_020500.dat to filename_20190415_020500.dat
Fetching /home/edvin/Test_folder/filename_20190415_020600.dat to filename_20190415_020600.dat
Fetching /home/edvin/Test_folder/filename_20190415_020700.dat to filename_20190415_020700.dat
Fetching /home/edvin/Test_folder/filename_20190415_020800.dat to filename_20190415_020800.dat
Fetching /home/edvin/Test_folder/filename_20190415_020900.dat to filename_20190415_020900.dat
Fetching /home/edvin/Test_folder/filename_20190415_021000.dat to filename_20190415_021000.dat
sftp> bye
There is many thing can go wrong still in this solution,
like if remote directory not exist, not accessible, script will still go on with the rest of the command, same for the local directory and for the files as well. The connection also can run various problems you might want to handle. You like to schedule it so might a solution needed to avoid script spawn over and over again if one already run.
scp would be more preferred way to do this, as you use password less authentication.
If scp is not an option for some reason, with expect this can be handled quite well.
I need a Bash script to accept 1 argument representing a time in hhmmss format, and from that derive a second time 3 minutes before that.
I've been trying to use date -d:
#! /bin/bash
DATE=`date +%Y%m%d`
TIME=$1
NEWTIME=`date -d "$DATE $TIME - 3 minutes" +%H%M%S`
echo $NEWTIME
In action:
$ ./myscript.sh 123456
invalid date `20141022 123456 - 3 minutes'
It seems the problem is with the 6 character time format because 4 characters (eg 1234) works. The subtraction of the 3 minutes is not the problem because I get the same error when I remove it.
It has occurred to me I could parse the time into a more palatable format before sending it to date. I tried inserting delimiters by adding this line:
TIME=${TIME:0:2}:${TIME:2:2}:${TIME:4:2}
It accepted that format but the answer to the - 3 minutes part was inexplicably very wrong (it subtracted 2 hours and 1 minute):
$ ./myscript.sh 123456
103356
Vexing.
It has also occurred to me that I might be able to provide date with an input format, like strptime which I'm familiar with from Python. I've found references to strptime in the context of Bash but I've been unable to get it to do anything.
Does anyone have any suggestions on getting the hhmmss time-string to work? Any help is much appreciated.
FYI: I'm trying to avoid changing the 6 character input format because that would involve changing other scripts as well as getting certain human users to alter long-entrenched habits. I'm also trying to avoid outsourcing this task to another language. (I could easily do this in Python). I want a Bash solution to this problem, if there is one.
TIME=093000
TIME=${TIME:0:2}:${TIME:2:2}:${TIME:4:2} # your line
date -d "2014-10-20 $TIME 3 mins ago" +%H%M%S
Output:
092700
I have a bash script that is sending me a text daily, for 100 days.
#! /bin/bash
EMAIL="my-phone-gateway#address.net"
MESSAGE="message_content.txt"
mail $EMAIL < $MESSAGE
Using crontab, I can have the static $MESSAGE sent to me every day.
Other than hard-coding 100 days of texts ;)
How could I implement a variable counter such that I can have my texts say:
"Today is Day #1" on the first day, "Today is Day #2" on the second day, etc. ?
Note: The location of the requested text within the $MESSAGE file doesn't matter. Last line, first line, middle, etc.
The only requirement for an answer here is that I know what day it is relative to the first, where the first day is the day the script was started.
Of course, bonus awesome points for the cleanest, simplest, shortest solution :)
For our nightly build systems, I wrote a C program that does the calculation (using local proprietary libraries that store dates as a number of days since a reference date). Basically, given a (non-changing) reference date, it reports the number of days since the reference date. So, the cron script would have a hard-wired first day in it, and the program would report the number of days since then.
The big advantage of this system is that the reference date doesn't change (very often), so the script doesn't change (very often), and there are no external files to store information in.
There probably are ways to achieve the same effect with standard Unix tools, but I've not sat down and worked out the portable solution. I'd probably think it terms of using Perl. (The C program only works up to 2999 CE; I left a note in the code for people to contact me about 50 years before it becomes a problem for the Y3K fix. It is probably trivial.)
You could perhaps work in terms of Unix timestamps...
Create a script 'days_since 1234567890' which treats the number as the reference date, gets the current time stamp (from date with appropriate format specification; on Linux, date '+%s' would do that job, and it works on Mac OS X too), takes the difference and divides by 86,400 (the number of seconds in a day).
refdate=1234567890
bc <<EOF
scale=0
($(date '+%s') - $refdate) / 86400
EOF
An example:
$ timestamp 1234567890
1234567890 = Fri Feb 13 15:31:30 2009
$ timestamp
1330027280 = Thu Feb 23 12:01:20 2012
$ refdate=1234567890
$ bc <<EOF
> scale=0
> ($(date '+%s') - $refdate) / 86400
> EOF
1104
$
So, if the reference date was 13th Feb 2009, today is day 1104. (The program bc is the calculator; its name has nothing to do with Anno Domini or Before Christ. The program timestamp is another homebrew of mine that prints timestamps according to a format that can be specified; it is a specialized variant of date originally written in the days before date had the functionality, by which I mean in the early 1980s.)
In a Perl one-liner (assuming you specify the reference date in your script):
perl -e 'printf "%d\n", int((time - 1234567890)/ 86400)'
or:
days=$(perl -e 'printf "%d\n", int((time - 1234567890)/ 86400)')
The only way to accomplish this would be to store the date in a file, and read from that file each day. I would suggest storing the epoch time.
today=$(date +%s)
time_file="~/.first_time"
if [[ -f $time_file ]]; then
f_time=$(< "$time_file")
else
f_time=$today
echo "$f_time" > "$time_file"
fi
printf 'This is day: %s\n' "$((($today - $f_time) / 60 / 60 / 24))"
Considering that your script is running only once a day, something like this should work:
#!/bin/bash
EMAIL="my-phone-gateway#address.net"
MESSAGE="message_content.txt"
STFILE=/tmp/start.txt
start=0
[ -f $STFILE ] && start=$(<$STFILE)
start=$((start+1))
MESSAGE=${MESSAGE}$'\n'"Today is Day #${start}"
echo "$start" > $STFILE
mail $EMAIL < $MESSAGE
A simple answer would be to export the current value to an external file, and read that back in again later.
So, for example, make a file called "CurrentDay.dat" that has the number 1 in it.
Then, in your bash script, read in the number and increment it.
e.g. your bash script could be:
#!/bin/bash
#Your stuff here.
DayCounter=$(<CurrentDay.dat)
#Use the value of DayCounter (i.e. $DayCounter) in your message.
DayCounter=$((DayCounter + 1))
echo $DayCounter > CurrentDay.dat
Of course, you may need to implement some additional checks to avoid something going wrong, but that should work as is.