+++ /dev/null
-#!/usr/bin/env bash
-
-# Note: GNU Parallel obviates the need for this script. The main
-# motivation to writing this script was to manage the number of CPU
-# threads being spawned by a list of files being feed to a while loop.
-
-# Functions
-yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
-die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
-try() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
-count_jobs() {
- # Desc: Count and return total number of jobs
- # Usage: count_jobs
- # Input: None.
- # Output: stdout integer number of jobs
- # Depends: Bash 5.1.16
- # Example: while [[$(count_jobs) -gt 0]]; do echo "Working..."; sleep 1; done;
- # Version: 0.0.1
-
- local job_count;
- job_count="$(jobs -r | wc -l | tr -d ' ' )";
- #yell "DEBUG:job_count:$job_count";
- if [[ -z $job_count ]]; then job_count="0"; fi;
- echo "$job_count";
-}; # Return number of background jobs
-test_job() {
- #yell "DEBUG:starting test_job() with:$1";
- # Do work on $1 file
- if [[ -f $1 ]]; then cat "$1" 1>/dev/random 2>&1; fi; # read file
- sleep "$(shuf -i1-10 -n1)"; # debug
-}; # Test job
-count_jobs_display_update() {
- # Depends: various variables
- if [[ $(( SECONDS % jobs_update_interval )) -eq $jobs_update_init_delay ]] && \
- [[ $permit_update == "true" ]]; then
- jobs_beg="$jobs_n";
- jobs_run="$(count_jobs)";
- jobs_end="$((jobs_beg - jobs_run))";
- yell "STATUS:$jobs_beg jobs begun. $jobs_end jobs ended. $jobs_run jobs running.";
- permit_update="false";
- fi;
- if [[ $(( SECONDS % jobs_update_interval )) -eq $((jobs_update_init_delay + 1)) ]]; then
- permit_update="true";
- fi;
-}; # periodically display updates
-
-
-# Test Code
-path_target="/tmp"; # path to dir with files to run test_job() on
-
-## Setup file list
-list_paths="$(find "$path_target" -type f 2>/dev/null)";
-
-## Perform test_job() on each file
-jobs_max=100; # adjust me (e.g. "4" on 4-core CPU)
-jobs_update_interval=5; # seconds.
-jobs_update_init_delay=1; # seconds.
-permit_update="true"; # flag to make updates happen periodically
-jobs_n=0; # loop counter
-jobs_check_delay=0.001; # seconds between each job count check if running jobs > jobs_max
-while read -r line; do
- ((jobs_n++));
- #yell "DEBUG:jobs_n:$jobs_n"
-
- ## Wait until job count falls below $jobs_max
- while [[ "$(count_jobs)" -gt $jobs_max ]]; do
- #yell "DEBUG:sleeping since $(count_jobs) > $jobs_max";
- sleep "$jobs_check_delay";
- count_jobs_display_update;
- done;
-
- ## Start new parallel job on file $line
- test_job "$line" 1>/dev/null 2>&1 &
-
- ## Get job status updates every $jobs_update_interval seconds
- count_jobs_display_update;
-
- #sleep 1; # debug
-done < <( shuf < <(echo -n "$list_paths") );
-yell "STATUS:All jobs ($jobs_n) started. $(count_jobs) jobs running.";
-
-# Detect when no outstanding jobs
-while [[ "$(count_jobs)" -gt 0 ]]; do
- sleep 1;
- count_jobs_display_update;
-done;
-yell "STATUS:No more jobs visible.";
-
-# Author: Steven Baltakatei Sandoval
-# License: GPLv3+