Cat Vs File Redirect

Redirection from file was about 10X+ times faster than using cat and this was done with my heavily loaded bash environmet which makes $() not su efficient.

#!/usr/bin/env bash
 
file=/tmp/hi
cat_file(){
  cat ${file:?} >&2
}
 
redirect_file(){
  contents="$(< "${file:?}")"
  echo "${contents:?}" >&2
}
main() {
  echo.log "Wrote to file [${file:?}]"
  date > ${file:?}
 
  benchmark 100 cat_file
  benchmark 100 redirect_file
}
 
main "${@}"

Benchmarker finished for [cat_file] args=[]

Metric	(millis)	(millis)
Min	1	0.645
P50 (Median)	1	1.233
P90	1	1.474
P95	2	1.589
P99	2	1.856
Max	2	2.075
Total	118	117.724
Iterations	100

Benchmarker finished for [redirect_file] args=[]

Metric	(micros)	(millis)
Min	31	0.031
P50 (Median)	32	0.032
P90	34	0.034
P95	38	0.038
P99	49	0.049
Max	97	0.097
Total	3,350	3.350
Iterations	100