How to get sar command value in 24 hour format (from 00:00:00 to 23:59:59) in Linux?

Question

I want to generate a file which has cpu usage logs in 24 hour format (from 00:00:00 to 23:59:59). I am using sar command but it gives time in AM or PM format which is not required.

Sample:

12:01:01 AM     all      1.33      0.00      1.06      0.24      0.00     97.37
12:02:01 AM     all      1.30      0.00      1.02      0.04      0.00     97.64

Expected result:

00:01:01 all      1.33      0.00      1.06      0.24      0.00     97.37
00:02:01 all      1.30      0.00      1.02      0.04      0.00     97.64

Answer 1

The sar program is a so-called locale aware program. Meaning it's output format is controlled by the LC_* environment variables. The variable LC_TIME is responsible for the output of time data. (see man locale).

Looks like you are using a system where LC_TIME is set to en_US - a locale using the 12hours AM/PM format (or LC_TIME was kept empty which will lead to using the default locale). You need to use a locale setting which is using the 24 hour format. Lets say en_UK. You can specify it on the command line:

LC_TIME=en_UK.utf8 sar

Output:

Linux 3.13.0-44-generic (desktop1)  01/22/15    _x86_64_    (4 CPU)

00:00:01        CPU     %user     %nice   %system   %iowait    %steal     %idle
00:02:01        all      2,26      0,00      0,41      0,71      0,00     96,63
00:04:01        all      2,68      0,00      0,72      0,46      0,00     96,13
...

---

Note! If the locale en_UK.uft8 isn't available on your system, you need to generate it using:

sudo locale-gen en_UK.utf8

or you can use POSIX or C:

LC_TIME='POSIX' sar
LC_TIME='C' sar