Here is a very nice article that you may find useful
https://access.redhat.com/discussions/469323
Link to this post!
change the output format for time command
If you are doing some scripting and using ‘time’ command, then you know sometimes it becomes difficult to capture the output as the output would be something like this:
: amit ; time ls real 0m0.002s user 0m0.000s sys 0m0.001s
So, it is better to change that format. Here is simple example:
-
1
- TIMEFORMAT=’real %3R user %3U sys %3S pcpu %P’ time ls
- amit ; TIMEFORMAT=’real %3R user %3U sys %3S pcpu %P’ time ls
- 0.00user 0.00system 0:00.00elapsed 0%CPU (0text+0data 2432max)
- 0inputs+0outputs (0major+109minor)pagefaults 0swaps
- amit ; TIMEFORMAT=’real %3R user %3U sys %3S’
- amit ; time ls
real 0.001 user 0.001 sys 0.000 - amit ;
- amit ; TIMEFORMAT=’TIMEOUTPUT = real %3R user %3U sys %3S’
- amit ; time ls
TIMEOUTPUT = real 0.001 user 0.001 sys 0.000 - amit ;
Link to this post!
Generate random string for various use case
Some times I need random string, for example to use as email seperator or to use in some API. One way is to use tools like /dev/[u]random or od and other such. But they seem cubersome after I figured this out.
openssl rand <length> openssl rand 10
This alone without some parameters is not interesting thoug. You can use ‘-base64’ or ‘-hex’ to select the encoding.
So if you execute the above you will get something like this
$ openssl rand -hex 10 591e96110af8aecb760b $ openssl rand -base64 10 TnuUXuiZXv2ktw==
Link to this post!