bash check if a file exists ([ -f file ], [ -e ], [ -d ])

if [ -f "$file" ]; then ...; fi checks whether $file exists and is a regular file. Use -d for a directory, -e for any kind of file system entry, and ! to negate ([ ! -f "$file" ]). Quote the variable and keep the spaces inside the brackets: [ is a command and ] its last argument.

The common tests

mkdir -p logs
echo "data" > config.ini
: > empty.txt

for path in config.ini empty.txt logs nope.txt "my file.txt"; do
  printf '%-12s' "$path"
  [ -e "$path" ] && printf ' exists' || printf ' missing'
  [ -f "$path" ] && printf ' file'
  [ -d "$path" ] && printf ' directory'
  [ -s "$path" ] && printf ' non-empty'
  [ -r "$path" ] && printf ' readable'
  echo
done

if [ ! -f settings.json ]; then
  echo "settings.json not found, using defaults"
fi

[[ -f config.ini && -d logs ]] && echo "config and logs present"

config.ini   exists file non-empty readable
empty.txt    exists file readable
logs         exists directory readable
nope.txt     missing
my file.txt  missing
settings.json not found, using defaults
config and logs present

empty.txt exists but fails -s (size greater than zero), logs is a directory and not a file, and names with spaces work because "$path" is quoted.

Test operators

Short forms

[ -f "$file" ] || { echo "missing: $file" >&2; exit 1; }   # stop the script if missing
[ -d "$dir" ] || mkdir -p "$dir"                           # create only if absent
test -f "$file" && source "$file"                          # test is the same as [ ]

Pitfalls

• Missing spaces. [-f "$file"] runs a command named [-f and fails with command not found; if [ -f "$file"] reports [: missing ']'.
• Unquoted variables. If $file is empty, [ -f $file ] becomes [ -f ], which is true (a single non-empty argument). With spaces in the name it becomes several arguments and fails with too many arguments. Quote it, or use [[ ]].
• Race conditions. Checking and then using a file is not atomic; another process can delete it in between. For important work, just open the file and handle the error.
• Globs. [ -f *.log ] fails with too many arguments when several files match; loop over them, or use compgen -G "*.log" > /dev/null to test whether any match.

Confirm it worked

Run [ -f path ]; echo $?: 0 means the test is true, 1 false, and 2 a syntax error in the test itself (see bash exit codes).

FAQ