64 lines
1.5 KiB
Bash
64 lines
1.5 KiB
Bash
|
#!/bin/bash
|
||
|
|
|
||
|
|
#-------------------------------------------------------------------------------
|
||
|
|
# Example 2 for Bash Tips show 19: the mapfile/readarray command
|
||
|
|
#-------------------------------------------------------------------------------
|
||
|
|
|
||
|
|
#
|
||
|
|
# Declare an indexed array
|
||
|
|
#
|
||
|
|
declare -a map
|
||
|
|
|
||
|
|
#
|
||
|
|
# Fill the array with a process substitution that generates 10 random numbers,
|
||
|
|
# each followed by a newline (the default delimiter). We remove the newline
|
||
|
|
# characters.
|
||
|
|
#
|
||
|
|
mapfile -t map < <(for i in {1..10}; do echo $RANDOM; done)
|
||
|
|
|
||
|
|
#
|
||
|
|
# Show the array as a list
|
||
|
|
#
|
||
|
|
echo "map: ${map[*]}"
|
||
|
|
echo
|
||
|
|
|
||
|
|
#
|
||
|
|
# Declare a new indexed array
|
||
|
|
#
|
||
|
|
declare -a daffs
|
||
|
|
|
||
|
|
#
|
||
|
|
# Define a string with spaces replaced by underscores
|
||
|
|
#
|
||
|
|
words="I_wandered_lonely_as_a_Cloud_That_floats_on_high_o'er_vales_and_Hills,_When_all_at_once_I_saw_a_crowd,_A_host,_of_golden_Daffodils"
|
||
|
|
|
||
|
|
#
|
||
|
|
# Fill the array with a process substitution that provides the string. The
|
||
|
|
# delimiter is '_' and we remove it as we load the array
|
||
|
|
#
|
||
|
|
mapfile -d _ -t daffs < <(echo -n "$words")
|
||
|
|
|
||
|
|
#
|
||
|
|
# Show the array as a list
|
||
|
|
#
|
||
|
|
echo "daffs: ${daffs[*]}"
|
||
|
|
echo
|
||
|
|
|
||
|
|
#
|
||
|
|
# Fill an array with 100 random dictionary words. Use 'printf' as the callback
|
||
|
|
# to report every 10th word using -C and -c
|
||
|
|
#
|
||
|
|
declare -a big
|
||
|
|
mapfile -t -C "printf '%02d %s\n' " -c 10 big < <(grep -E -v "'s$" /usr/share/dict/words | shuf -n 100)
|
||
|
|
echo
|
||
|
|
|
||
|
|
#
|
||
|
|
# Report every 10th element of the populated array in the same way
|
||
|
|
#
|
||
|
|
echo "big: ${#big[*]} elements"
|
||
|
|
for ((i = 9; i < ${#big[*]}; i=i+10)); do
|
||
|
|
printf '%02d %s\n' "$i" "${big[$i]}"
|
||
|
|
done
|
||
|
|
|
||
|
|
exit
|