TIL there's another 'time' command that gives some pretty useful stats about the program's resource use

Posted by dtdisapointingresult@reddit | linux | View on Reddit | 2 comments

You may already know about "time some-command" shell command to measure how long a command took, but I found out distros ship with a superior alternative that has a handy verbose flag. You just gotta call it explicitly by using /usr/bin/time instead of time. Example output: $ /usr/bin/time -v make -j `nproc` Command being timed: "make -j 8" User time (seconds): 875.27 System time (seconds): 315.99 Percent of CPU this job got: 638% Elapsed (wall clock) time (h:mm:ss or m:ss): 3:06.65 Average shared text size (kbytes): 0 Average unshared data size (kbytes): 0 Average stack size (kbytes): 0 Average total size (kbytes): 0 Maximum resident set size (kbytes): 608940 Average resident set size (kbytes): 0 Major (requiring I/O) page faults: 0 Minor (reclaiming a frame) page faults: 362743651 Voluntary context switches: 50611 Involuntary context switches: 72616 Swaps: 0 File system inputs: 0 File system outputs: 687952 Socket messages sent: 0 Socket messages received: 0 Signals delivered: 0 Page size (bytes): 4096 Exit status: 2 I'm wondering though, what IS the default 'time' command in bash? It's not listed in the [bash doc's built-ins](https://www.gnu.org/software/bash/manual/html_node/Shell-Builtin-Commands.html). Does using 'time' actually call /usr/bin/time somehow with different flags?