Shell Programming and Scripting

if [-f find <path> -mtime 4 -print ]
then <some tasks>
else
echo "file not exists"
fi

 find <path> -mtime 4 -print 2>/dev/null | while read file; do echo "process the file $file"; done

find /path -type f -name "filename" | while read a;
do
echo "do process here"
done

if [ -f filename.txt ]
then
    echo "file present"
else
   echo "no file"
fi

touch -t  201207050000  dummy1
touch -t 201207052359 dummy2
find /path/to/files \( -newer dummy1 -a  ! -newer dummy2 \) |
while read filename
do
    # some tasks on $filename
done

my_hitlist=/tmp/my_hitlist.$$
start_dir="/path/to/start/directory"
filename="the_name_of_the_file"
find "${start_dir}" -xdev -name "${filename}" -type f -print 2>/dev/null > ${my_hitlist}
# Did we find any files?
if [ -s ${my_hitlist} ]
then
       # Do some tasks
else
       echo "File does not exist: ${start_dir}/${filename}"
fi