#!/usr/bin/env bash
# Desc: Mixes input lines while also preserving some neighbors
# Usage: cat file | bkshuf arg1
-# Version 0.0.1
+# Version 0.2.0
# Depends: bc 1.07.1, GNU Coreutils 8.32 (shuf)
# Input: var: arg1 initial lines to output
-BKSHUF_PARAM_LINEC=1000000;
-BKSHUF_PARAM_GSIZE=25 # lines per group for BKSHUF_PARAM_LINEC lines of input
+trap 'exit;' SIGPIPE; # exit early if stdout not being read
+
+# Load env vars
+## For these numbers of lines of input...
+if [[ ! -v BKSHUF_PARAM_LINEC ]]; then BKSHUF_PARAM_LINEC=1000000; fi;
+## ... target this group size.
+if [[ ! -v BKSHUF_PARAM_GSIZE ]]; then BKSHUF_PARAM_GSIZE=25; fi;
yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
line="${list_input[$ip]}";
if [[ -n $line ]]; then
##### consume line at index ip
- printf "%s\n" "$line" & # print to output
+ printf "%s\n" "$line"; # print to output
+
unset "list_input[$ip]"; # destroy line in list_input array
((lc_out++));
((lcr--)); # decrement line count remaining lcr
else
lc_out_max="$1"; # output line count
fi;
-
+
+ # Check env vars
+ if ! checkInt "$BKSHUF_PARAM_LINEC"; then
+ die "FATAL:Not an int:BKSHUF_PARAM_LINEC:$BKSHUF_PARAM_LINEC"; fi;
+ if ! checkInt "$BKSHUF_PARAM_GSIZE"; then
+ die "FATAL:Not an int:BKSHUF_PARAM_LINEC:$BKSHUF_PARAM_GSIZE"; fi;
# store input lines from stdin (like `shuf`)
while read -r line; do
lc_out="0"; # init output line counter
if [[ -z "$lc_out_max" ]]; then lc_out_max="$lco"; fi;
ip="$(shuf -i0-$(( lco - 1 )) -n1)"; # init input index pointer
+ RANDOM="$(shuf -i0-32767 -n1)"; # init Bash PRNG
n_loop1="0";
#yell "DEBUG:max_blanks:$max_blanks"
while [[ $lcr -ge 1 ]] && [[ $lc_out -lt $lc_out_max ]]; do