The folder does not exist and is created
if [!-d "/data/"];thenmkdir/dataelseecho "folder already exists" fi
File exists then delete
if [!-F "/data/filename"];thenecho "file does not exist" Elserm-rf/data/filenamefi
Determine if a folder exists
If [-d '/data/"];thenecho" folder exists "Elseecho" folder does not exist "fi
Determine if a file exists
If [-d '/data/test "];thenecho" file exists "Elseecho" file does not exist "fi
File comparison characters
-e filename if filename exists, true [-e/var/log/syslog]-d filename if filename is directory, true [-d/tmp/mydir]-f fi Lename True if filename is a regular file [-f/usr/bin/grep]-l filename If filename is a symbolic link, true [-l/usr/bin/grep]-r FileName If filename is readable, true [-r/var/log/syslog]-w filename If filename is writable, true [-w/var/mytmp.txt]- x filename If filename is executable, true [-l/usr/bin/grep]filename1-nt filename2 If filename1 is newer than filename2, true c15/>[/tmp/install/etc/services-nt/etc/services]filename1-ot filename2 If filename1 is older than filename2, then true [/ Boot/bzimage-ot Arch/i386/boot/bzimage]
Shell determines whether a folder or file exists