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