Timer

Get the execution time of the script or sql query.

PHP

• Start and stop a timer PHP - Stack Overflow
• Accurate way to measure execution times of php scripts - Stack Overflow

MySQL

Recording the time elapsed after the sql query was executed.

SELECT @timer := CURRENT_TIMESTAMP();
SELECT SLEEP(2); /* sleep 2 seconds for testing purpose */
SELECT 'custom message' AS 'action', CURRENT_TIMESTAMP() AS 'finish time', @timer AS 'start time', TIMEDIFF(CURRENT_TIMESTAMP(), @timer) AS 'time elapsed';

Linux command (BASH)

Linux console, macOS Terminal or Cygwin commands on Win

# start the timer
START=$(date +%s)

# sleep 2 seconds for testing purpose
sleep 2s

# stop the timer
END=$(date +%s)
DIFF=$(( $END - $START ))
printf "Elapsed time %02dh:%02dm:%02ds\n" $(($DIFF/3600)) $(($DIFF%3600/60)) $(($DIFF%60))

# expected result: 
#   Elapsed time 00h:00m:02s

This following script measures elapsed time with millisecond precision

# start the timer
START=$(date +%s.%N)

# sleep 2 seconds for testing purpose
sleep 2s

# stop the timer
END=$(date +%s.%N)
DIFF=$(awk "BEGIN {printf \"%.3f\", $END - $START}")

# Use awk to break the seconds down into h/m/s while preserving the decimal part
printf "Elapsed time %s\n" "$(awk -v t="$DIFF" 'BEGIN {
    h = int(t/3600)
    m = int((t%3600)/60)
    s = t%60
    printf "%02dh:%02dm:%06.3fs", h, m, s
}')"

# expected result:
#   Elapsed time 00h:00m:02.002s

Windows command (DOS)

REM show the start time
prompt $d $t $_$P$G

REM do something ...

REM show the finish time
prompt $d $t $_$P$G

or ...

REM start to record the start time
set startTime=%time%

REM do something ...

REM show the start and finish time
echo Start Time: %startTime%
echo Finish Time: %time%

Python

Using time.time()

import time

# start the timer
start = time.time()

# do something

# stop the timer
end = time.time()
print("Elapsed time in seconds: ", end - start)

Javascript

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

// 1 second = 1000 ms
var startTimeInMs = Date.now();

await sleep(2000);

var endTimeInMs = Date.now();
var durationInMs = endTimeInMs - startTimeInMs;
console.log('durationInMs: ' + durationInMs);

var durationInSecond = durationInMs / 1000;
console.log('durationInSecond: ' + durationInSecond);

Reference

• What is the Javascript alternative to the sleep function?
• 在 JavaScript 簡單取得 unix timestamp

Java

Java.lang.System.currentTimeMillis()

# start the timer
long start_time = System.currentTimeMillis();

# stop the timer
System.out.println("\nElapsed time: " + (System.currentTimeMillis() - start_time) + " ms");

References