I need a bash script that sets a date for my program. The program must work with a date different from the current one. Is it possible? With:
#!/bin/sh
date 122511462014.30 && myprogram
I get the following message error
date: cannot set date: Operation not permitted
because my script runs with no root privileges.
You can't do it like that. date changes the date for the entire system.
You need something like libfaketime
Related
I want to print the date after every bash command I run.
This could help me understand how much a command took to execute when I am away from keyboard.
I know I could do
`DATE=`date +%d/%m/%Y\ %H:%M:%S` && echo $DATE`
to get the date but I don't know how or even if it could be possible to run this command after every command I execute on bash.
I would also be interested in running the same command before every command so I could know how long a command took.
Is it possible?
What file should I edit?
For example:
$ wget google.com
15/07/2017 23:40:05
I would be happy, if I could also introduce this following feauture:
$ wget google.com
15/07/2017 23:40:05 15/07/2017 23:40:11
Program run for 00:00:06
where the first date is when I ran the program, second is when program terminated the third is self-explanatonary.
As you understood, I don't want to type every time
$ wget google.com && `DATE=`date +%d/%m/%Y\ %H:%M:%S` && echo $DATE`
To execute a cmd before every command entered, set a trap on DEBUG. Eg.
trap date DEBUG
To execute that command before emitting a prompt, set PROMPT_COMMAND:
PROMPT_COMMAND=date
This does exactly that:
PROMPT_COMMAND+=$'\n'"date +%d/%m/%Y\ %H:%M:%S"
The string in PROMPT_COMMAND gets evaluated after every command. You just need to add the date command to whatever you already had in it. ($'\n' (newline) is a somewhat more robust joiner than ; as two consecutive ; would give you a syntax error)
You can add date/time to your prompt, via PS1 variable. You could use date command, but it's more efficient to use the supported special characters, like \d for date, or \D{strftime-fmt}.
For example:
PS1='\u#\h[\D{%F} \D{%T}]\w\$ '
or, with color:
PS1='\[\033[01;32m\]\u#\h\[\033[00m\][\[\033[02;33m\]\D{%F}\[\033[08m\]T\[\033[00m\]\[\033[02;33m\]\D{%T}\[\033[00m\]]\[\033[01;34m\]\w\[\033[00m\]\$ '
will show:
user#host[2017-07-16 00:01:17]~/somedir$
Note that in the second case (with color) we have a valid ISO8601 timestamp, with a "hidden" date/time separator T in the middle. If you select it with a mouse, T is visible and can be copied. (Also double-click will select the complete timestamp, not only date or time.)
To print timestamp after every command just modify your PS1 prompt and add date to it. The only catch here is that it will tell you time when command ended and new prompt showed. So in case you have your prompt open for long time just hit enter to capture start time before running your command.
PS1="\D{%F %T} \$ "
See this arch wiki page or just google bash prompt customization.
To add time spent executing program just add time before the command
$ time wget google.com
It will give you output like this
real 0m0.177s
user 0m0.156s
sys 0m0.020s
And you can get even more lazy and for commands that you dont't feel like typing time every time you run it, just create alias.
alias wget="time wget"
Because in bash aliases are run before other commands you can do it this way even if it looks like recursion. Then you will call it as you are used to.
And of course, aliases and prompt settings can be put in your .bashrc file, so you don't have to type them every time you open terminal.
I make a script in a command line, but I have a problem. I need change date automatically from a command line. Is it possible?
I know, I can use static date for example:
date 0101122315
but I need an automatic date from the internet in macOs.
You've probably got some research to do, here is one possible outline:
Use curl to have the date from the internet and store in a file or send to standard output - in the latter case you may pipe into more commands or store in a shell variable.
If needed: Use sed, awk, grep, some JSON editor, etc. to extract the date from the result of (1). Not needed if your URL just returns the date and nothing else.
Use date and shell variable or command output substitution to pass your date as an argument.
You can find documentation on all the commands, and the shell, using the man command, e.g. man curl.
You might end up with a short one line script (something like:
date `curl URL | sed command`
) or something longer. Nobody can really tell you as it is unstated in the question what the URL will return.
If you get stuck once you're further along ask a new question showing what you've developed and explains the error and someone will undoubtedly help you progress.
Have fun!
Try this command
sudo sntp -sS time.apple.com
So for the life of me I cannot figure out why my script will not take my date command as a variable. I have a script that is run every time a message is received and procmail filters specific messages by their subject line. The script looks like this:
d=$(date +%Y%m%d)
:0 wc
* ^(From|subject).*xxx
| cat&>/xx/xx/xx/xx/MSG:$d && \
chmod xxx /xx/xx/xx/xx/MSG:$d && \
/xx/xx/xx/otherscript.sh /xx/xx/xx/xx/MSG:$d
I have run the date command plenty of times in other scripts and to stdout without any issue, so I am wondering if this is a procmail issue? I have looked at a few different sites about this but still have not found a solution. My end goal is to create unique file names as well as for organization purposes each time a new email comes in.
The other reason for me believing it has something to do with procmail is that it was working fine just 3 months ago (didn't change any files or permissions). I have even tried several variations (only showing a few examples):
$'date +"%Y%m%d"'
$(date)
echo $(date)
I get a variety of files created ranging with it printing MSG:(date), MSG:(date ,etc. MSG:(date appears to like it tries to read the variable but is getting cut off or the space between date and + is causing an issue.
And at the end of my script I send it to another script which also creates a new file with the date appended and it works just fine:
fileOut="/xxx/xxx/xxx/xxx.$v.$(date +"%Y%m%d-%H%M%S").xxx"
prints: xxx.YH8AcFV9.20160628-090506.txt
Thanks for your time :-)
Procmail does not support the modern POSIX shell command substitution syntax; you need to use backticks.
d=`date +%Y%m%d` # or just date +%F
If you want to avoid invoking an external process, the From_ pseudo-header contains a fresh date stamp on many architectures.
In a bash script I have the following:
MES=$(date +"%b")
How can I get the month in english format?
Now if I echo $MES variable, I get abr. But I would like to get apr.
I'm trying to solve this without using if statement or switch. May be is an option...
I have tried date -u but is not working for me.
EDIT:
Finally I have put this line in the first line of script script:
#!/bin/bash
LANG=en_us_8859_1
# Here rest of the script
Now is working, but I can't accept my own answer as valid... I think because I haven't enough reputation in stackoverflow
Use Command Substitution
MES=$(LANG=en_us_88591; date +"%b")
to change the language just for this single call.
I have a script that pulls information from a file and outputs it to a different file. What i need to do is run this script everyday but output to a different file. I will have this in the crontab to run everyday at the same time but i dont know how to output to a different file everyday. Is there a loop i can use?
Regards,
John
You don't need a loop. Rather, use a stdout/stderr redirection to a filename created using 'date'
e.g.
$ myprocess.sh > `date +"%m-%d-%Y"`.log
so date is executed in the backticks (this is known as command substitution) and the output substituted in the line. Here the formatted output of date is used as the log file name (in this case 04-24-2014.log)