mjhjmtu

I am trying to create a find command options string using entries from an array but on the last entry of the array I would like to add a different string.

EXT=(sh mkv txt)

EXT_OPTS=(-iname)

# Now build the find command from the array
for i in "$EXT[@]"; do
 #echo $i
 EXT_OPTS+=( "*.$i" -o -iname)
done

cheers

EDIT:

So now I am going with:

#!/bin/bash

EXT=(sh mkv txt)

EXT_OPTS=()
# Now build the find command from the array
for i in "$EXT[@]"; do
 EXT_OPTS+=( -o -iname "*.$i" )
done

# remove the first thing in EXT_OPTS
EXT_OPTS=( "$EXT_OPTS[@]:1" )

# Modify to add things to ignore:

EXT_OPTS=( "$EXT_OPTS[@]:-1" )
EXT_OPTS=( '(' "$EXT_OPTS[@]" ')' ! '(' -iname "*sample*" -o -iname "*test*" ')' )

#echo "$EXT_OPTS[@]"

searchResults=$(find . -type f "$EXT_OPTS[@]")

echo "$searchResults"

for me produces this:

./Find2.sh
./untitled 2.sh
./countFiles.sh
./unrar.sh
./untitled 3.sh
./untitled 4.sh
./clearRAM.sh
./bash_test.sh
./Test_Log.txt
./untitled.txt
./Find.txt
./findTestscript.sh
./untitled.sh
./unrarTest.sh
./Test.sh
./Find.sh
./Test_Log copy.txt
./untitled 5.sh
./IF2.sh

Add the options in another order, then delete the first element:

EXT=(sh mkv txt)

EXT_OPTS=()
# Now build the find command from the array
for i in "$EXT[@]"; do
 EXT_OPTS+=( -o -iname "*.$i" )
done

# remove the first thing in EXT_OPTS
EXT_OPTS=( "$EXT_OPTS[@]:1" )

If you don't use $@ for anything, it's neater looking:

EXT=(sh mkv txt)

# Empty $@
set --

# Now build the find command from the array
for i in "$EXT[@]"; do
 set -- -o -iname "*.$i"
done

# remove the first thing in $@
shift

# assign to EXT_OPTS (this would be optional, you could just use "$@" later)
EXTS_OPTS=( "$@" )

I prefer adding -o -iname "*.$i" to the intermediate array, because "*.$i" -o -iname is difficult to read. Adding -o -iname "*.$i" to $@ also makes it really easy to just shift off the first -o after the loop.

To combine with a few exclusions (names to ignore):

extensions=( sh mkv txt )
ignore_patterns=( '*sample*' '*test*' )

include=()
# Now build the find command from the array
for ext in "$extensions[@]"; do
 include+=( -o -iname "*.$ext" )
done

# Do the ignore list:
ignore=()
for pattern in "$ignore_patterns[@]"; do
 ignore=( -o -iname "$pattern" )
done

# combine:
EXT_OPTS=( '(' "$include[@]:1" ')' ! '(' "$ignore[@]:1" ')' )

Note the parentheses added to sort out the precedence of the tests.

It will be easiest just to fix the array after the fact. After done, adding

unset 'EXT_OPTS[-1]'
unset 'EXT_OPTS[-1]'

will remove the last two values (-o and -iname), and then you can add others if you want (or just replace them to begin with).

It might be slightly easier still just to add a redundant condition:

EXT_OPTS+=( "*.$EXT[0]" )

if your real situation is a bit more complicated, but for this one I would just fix it as above.

Is there a way of determining the last entry when looping through an array?

Just to answer the question as literally stated, I don't think you can do that directly. But you could of course count the elements while looping and compare that against the array size:

test=(foo bar blah qwerty)
count=$#test[@]
n=1
for x in "$test[@]"; do
 last=""
 if [[ $((n++)) -eq count ]]; then
 last=" (last)" # last element, add a note about that
 fi
 printf "%s%sn" "$x" "$last"
done

Of course in your case, you could also make the first item the exceptional one.