This article explains how to find the time interval between two Unix time stamps. The default time format in Unix is like this: “Sun 9 Aug 12:50:08 BST 2020”. It appears in many places on the system and is the default produced by the “date” command.
For example, it might appear in application log files, like this::
Start time: Sun 9 Aug 10:05:00 BST 2020
End Time: Sun 9 Aug 12:51:12 BST 2020
This article explains how to subtract one time from the other in Bash, and obtain the intervening time in seconds.
The “sort” command on Solaris has a “-k” switch for sorting by a particular field. For example, “sort -k 2” will sort by the second field on each line of input. Parts of fields can be further specified with “-k n.m“, says the man page.
For example, “sort -k 2.3” should sort by the second field, starting with the third character in that field. But the man page isn’t the clearest, and getting the “-k x.y” notation to work is tricky. Tricky until you realize it never works you also supply the “-b” argument. Same on Linux. Continue reading →