CODEWITHSUNDEEP
bash
IcedCoffee
IcedCoffee

Reputation: 385

Alternative method in Bash for checking if file is present

I am currently running a script (check_files.sh) that may or may not produce match* files (eg. match1.txt, match2.txt, etc. I then want to go on to run an R script on the produced match* files.

However, before I run the R script, I have tried a line in my script which checks if the files are present.

if [ -s match* ]
            then
            for f in match*
            do
                Rscript --vanilla format_matches.R ${f}
                rm match*
            done
else
            echo "No matches present"
fi

However, I keep getting an error message (as there are often a lot of match files producted):

./check_files.sh: line 52: [: too many arguments

Is there an alternative to [ -s match* ] which would not throw up the error message? I take it that the error message appears as there are multiple match* files produced.

Upvotes: 0

Views: 100

Answers (3)

xvan
xvan

Reputation: 4875

If you expect filenames with spaces, this is a bit ugly but robust:

found=0
find -maxdepth 1 -type f -name 'match*' -print0 | while IFS= read -rd $'\0' f
do 
    found=1
    Rscript --vanilla format_matches.R "$f"
    rm "$f"
done

if [ "$found" -eq 0 ]; then
    >&2 echo "No matches present"
fi

Upvotes: 2

dufte
dufte

Reputation: 249

Is there an alternative to [ -s match* ] which would not throw up the error message?

The following works for my example file match1.txt

if [ -f ~/match* ]; then
  echo "yeha"
fi

Upvotes: 0

Andreas Louv
Andreas Louv

Reputation: 47137

You could change your logic to the following:

found=0
for f in match*; do
    [ -e "$f" ] || continue
    found=1
    Rscript --vanilla format_matches.R "$f"
    rm "$f"
done

if [ "$found" -eq 0 ]; then
    >&2 echo "No matches present"
fi

Upvotes: 2

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