Guida avanzata di scripting Bash - Portale Posta DMI

# # # Remove the above "# " to disable this code. # # #
Appendice A. Script aggiuntivi
_pls() {
local IFS=$’x1B’ # \ESC character (not required)
echo $’\x27’$@$’\x27’ # Hard quoted parameter glob
}
# Declare an array for test values.
declare -a arrayZ
# Assign elements with various types of quotes and escapes.
arrayZ=( zero "$(_pls ’Hello ${Me}’)" ’Hello ${You}’ "\’Pass: ${pw}\’" )
# Now make an assignment with that result.
declare -a array2=( ${arrayZ[@]} )
# Which yielded:
# - - Test Three - -
# Element 0: zero is: 4 long # Our marker element.
# Element 1: Hello ${Me} is: 11 long # Intended result.
# Element 2: Hello is: 5 long # ${You} expanded to nothing.
# Element 3: ’Pass: is: 6 long # Split on the whitespace.
# Element 4: ’ is: 1 long # The end quote is here now.
# set -vx
# Initialize ’Me’ to something for the embedded ${Me} substitution.
# This needs to be done ONLY just prior to evaluating the
#+ protected string.
# (This is why it was protected to begin with.)
Me="to the array guy."
# Set a string variable destination to the result.
newVar=$(_upls ${array2[1]})
# Show what the contents are.
echo $newVar
# Do we really need a function to do this?
newerVar=$(eval echo ${array2[1]})
echo $newerVar
# I guess not, but the _upls function gives us a place to hang
#+ the documentation on.
# This helps when we forget what a # construction like:
#+ $(eval echo ... ) means.
# What if Me isn’t set when the protected string is evaluated?
unset Me
newestVar=$(_upls ${array2[1]})
echo $newestVar
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