如何有效地获得脚本的执行时间？

#1 楼

time yourscript.sh

#2 楼

start=`date +%s`
stuff
end=`date +%s`

runtime=$((end-start))

#3 楼

ret=$?; times; exit "$ret"

trap times EXIT

$ bash -c 'trap times EXIT; : {1..1000000}'
0m0.932s 0m0.028s
0m0.000s 0m0.000s
$ zsh -c 'trap time EXIT; : {1..1000000}'
shell  0.67s user 0.01s system 100% cpu 0.677 total
children  0.00s user 0.00s system 0% cpu 0.677 total

#4 楼

res1=$(date +%s.%N)

# do stuff in here

res2=$(date +%s.%N)
dt=$(echo "$res2 - $res1" | bc)
dd=$(echo "$dt/86400" | bc)
dt2=$(echo "$dt-86400*$dd" | bc)
dh=$(echo "$dt2/3600" | bc)
dt3=$(echo "$dt2-3600*$dh" | bc)
dm=$(echo "$dt3/60" | bc)
ds=$(echo "$dt3-60*$dm" | bc)

LC_NUMERIC=C printf "Total runtime: %d:%02d:%02d:%02.4f\n" $dd $dh $dm $ds

#5 楼

# Reset BASH time counter
SECONDS=0
    # 
    # do stuff
    # 
ELAPSED="Elapsed: $(($SECONDS / 3600))hrs $((($SECONDS / 60) % 60))min $(($SECONDS % 60))sec"

#6 楼

main () {
 echo running ...
}

# stuff ...

# calling the function at the very end of the script
time main

#7 楼

perf stat -r 10 -B sleep 1

1.002248382 seconds time elapsed                   ( +-  0.01% )

#8 楼

#!/bin/bash
start=$(date +%s.%N)

# HERE BE CODE

end=$(date +%s.%N)    
runtime=$(python -c "print(${end} - ${start})")

echo "Runtime was $runtime"

#9 楼

tm() {
  local start=$(date +%s)
  $@
  local exit_code=$?
  echo >&2 "took ~$(($(date +%s)-${start})) seconds. exited with ${exit_code}"
  return $exit_code
}

tm the_original_command with all its parameters

#10 楼

#!/bin/csh
#PBS -q glean
#PBS -l nodes=1:ppn=1
#PBS -l walltime=10:00:00
#PBS -o a.log
#PBS -e a.err
#PBS -V
#PBS -M shihcheng.guo@gmail.com
#PBS -m abe
#PBS -A k4zhang-group
START=$(date +%s)
for i in {1..1000000}
do
echo 1
done
END=$(date +%s)
DIFF=$(echo "$END - $START" | bc)
echo "It takes DIFF=$DIFF seconds to complete this task..."

#11 楼

  $ time sleep 1

 real    0m1.011s
 user    0m0.004s
 sys 0m0.000s
 

  # time your "make" build
 time make

 # time your "Bazel" build
 time bazel build //path/to/some:target
 

  # time how long it takes to pull from a massive repo when
 # I'm working from home during COVID-19. NB: `git pull`
 # is sooooo much slower than just pulling the one branch
 # you need with `git pull origin <branch>`, so just fetch
 # or pull what you need!
 time git pull origin master
 

  start=$SECONDS; sleep 1; end=$SECONDS; dt_sec=$(( end - start )); \
 dt_min=$(printf %.3f $(echo "$dt_sec/60" | bc -l)); \
 echo "dt_sec = $dt_sec; dt_min = $dt_min"
 

  dt_sec = 1; dt_min = 0.017
 

#12 楼

start=$SECONDS

... # do time consuming stuff

end=$SECONDS

echo "duration: $((end-start)) seconds."

echo "duration: $((SECONDS-start)) seconds elapsed.."

let diff=end-start

#13 楼

time_it() {
  local start=$SECONDS ts ec
  printf -v ts '%(%Y-%m-%d_%H:%M:%S)T' -1
  printf '%s\n' "$ts Starting $*"
  "$@"; ec=$?
  printf -v ts '%(%Y-%m-%d_%H:%M:%S)T' -1
  printf '%s\n' "$ts Finished $*; elapsed = $((SECONDS-start)) seconds"
  # make sure to return the exit code of the command so that the caller can use it
  return "$ec"
}

time_it sleep 5

2019-03-30_17:24:37 Starting sleep 5 2019-03-30_17:24:42 Finished
sleep 5; elapsed = 5 seconds

#14 楼

start=$(date +%s)
end=$(date +%s)
runtime=$(python -c "print '%u:%02u' % ((${end} - ${start})/60, (${end} - ${start})%60)")

#15 楼

#!/bin/bash
begin=$(date +"%s")

Script

termin=$(date +"%s")
difftimelps=$(($termin-$begin))
echo "$(($difftimelps / 60)) minutes and $(($difftimelps % 60)) seconds elapsed for Script Execution."

#16 楼

time: time [-p] PIPELINE
    Execute PIPELINE and print a summary of the real time, user CPU time,
    and system CPU time spent executing PIPELINE when it terminates.
    The return status is the return status of PIPELINE.  The `-p' option
    prints the timing summary in a slightly different format.  This uses
    the value of the TIMEFORMAT variable as the output format.

TIMEFORMAT="The command took %Rs"
time {
    sleep 0.1
}

The command took 0.108s

#17 楼

# Preparations:
Cmd=vgs  # example of a program to be timed which is writing to stdout and stderr
Cmd="eval { echo stdout; echo stderr >&2; sleep 0.1; }"  # other example; replace with your own
TIMEFORMAT="%3R %3U %3S"  # make time output easy to parse

read Elapsed User System < <({ time $Cmd 2>&3; } 3>&2 2>&1 >&3)

{ read Elapsed User System < <({ time $Cmd 2>&4; } 4>&2 2>&1 >&3); } 3>&1

{ read Elapsed User System < <({ time $Cmd 2>&4 4>&-; } 4>&2 2>&1 >&3 3>&-); } 3>&1

CPU=`printf %04d $((10#${User/.}+10#${System/.}))`  # replace with your own postprocessing
echo CPU ${CPU::-3}.${CPU: -3} s, Elapsed $Elapsed s >&2  # redirected independent of $Cmd

File descriptor 3 (/dev/pts/1) leaked on vgs invocation. Parent PID 10756: bash
File descriptor 4 (/dev/pts/1) leaked on vgs invocation. Parent PID 10756: bash
  VG   #PV #LV #SN Attr   VSize VFree
  b3     3  24   0 wz--n- 1.31t 1.19t
CPU 0.052 s, Elapsed 0.056 s