XXX 7.2. File test operators¶

** Returns true if...**

-e	file exists
-a	file exists This is identical in effect to -e . It has been “deprecated,” ` [1] <fto.html#FTN.AEN3289>`__ and its use is discouraged.
-f	file is a `` regular `` file (not a directory or device file )
-s	file is not zero size
-d	file is a directory
-b	file is a block device
-c	file is a character device device0="/dev/sda2" # / (root directory) if [ -b "$device0" ] then echo "$device0 is a block device." fi # /dev/sda2 is a block device. device1="/dev/ttyS1" # PCMCIA modem card. if [ -c "$device1" ] then echo "$device1 is a character device." fi # /dev/ttyS1 is a character device.
-p	file is a pipe function show_input_type() { [ -p /dev/fd/0 ] && echo PIPE |echo STDIN } show_input_type "Input" # STDIN echo "Input"show_input_type # PIPE # This example courtesy of Carl Anderson.
-h	file is a symbolic link
-L	file is a symbolic link
-S	file is a socket
-t	file ( descriptor ) is associated with a terminal device This test option may be used to check whether the `` stdin `` `` [ -t 0 ] `` or `` stdout `` `` [ -t 1 ] `` in a given script is a terminal.
-r	file has read permission ( for the user running the test )
-w	file has write permission (for the user running the test)
-x	file has execute permission (for the user running the test)
-g	set-group-id (sgid) flag set on file or directory If a directory has the `` sgid `` flag set, then a file created within that directory belongs to the group that owns the directory, not necessarily to the group of the user who created the file. This may be useful for a directory shared by a workgroup.
-u	set-user-id (suid) flag set on file A binary owned by root with `` set-user-id `` flag set runs with root privileges, even when an ordinary user invokes it. ` [2] <fto.html#FTN.AEN3400>`__ This is useful for executables (such as pppd and cdrecord ) that need to access system hardware. Lacking the suid flag, these binaries could not be invoked by a non-root user. -rwsr-xr-t 1 root 178236 Oct 2 2000 /usr/sbin/pppd A file with the `` suid `` flag set shows an s in its permissions.
-k	`` sticky bit `` set Commonly known as the sticky bit, the save-text-mode flag is a special type of file permission. If a file has this flag set, that file will be kept in cache memory, for quicker access. ` [3] <fto.html#FTN.AEN3423>`__ If set on a directory, it restricts write permission. Setting the sticky bit adds a t to the permissions on the file or directory listing. This restricts altering or deleting specific files in that directory to the owner of those files. drwxrwxrwt 7 root 1024 May 19 21:26 tmp/ If a user does not own a directory that has the sticky bit set, but has write permission in that directory, she can only delete those files that she owns in it. This keeps users from inadvertently overwriting or deleting each other’s files in a publicly accessible directory, such as `` /tmp `` . (The owner of the directory or root can, of course, delete or rename files there.)
-O	you are owner of file
-G	group-id of file same as yours
-N	file modified since it was last read

f1 -nt f2

file `` f1 `` is newer than `` f2 ``

f1 -ot f2

file `` f1 `` is older than `` f2 ``

f1 -ef f2

files `` f1 `` and `` f2 `` are hard links to the same file

!

“not” – reverses the sense of the tests above (returns true if

condition absent).

#!/bin/bash
# broken-link.sh
# Written by Lee bigelow <ligelowbee@yahoo.com>
# Used in ABS Guide with permission.

#  A pure shell script to find dead symlinks and output them quoted
#+ so they can be fed to xargs and dealt with :)
#+ eg. sh broken-link.sh /somedir /someotherdir|xargs rm
#
#  This, however, is a better method:
#
#  find "somedir" -type l -print0|\
#  xargs -r0 file|\
#  grep "broken symbolic"
#  sed -e 's/^\|: *broken symbolic.*$/"/g'
#
#+ but that wouldn't be pure Bash, now would it.
#  Caution: beware the /proc file system and any circular links!
################################################################


#  If no args are passed to the script set directories-to-search
#+ to current directory.  Otherwise set the directories-to-search
#+ to the args passed.
######################

[ $# -eq 0 ] && directorys=`pwd` |directorys=$@


#  Setup the function linkchk to check the directory it is passed
#+ for files that are links and don't exist, then print them quoted.
#  If one of the elements in the directory is a subdirectory then
#+ send that subdirectory to the linkcheck function.
##########

linkchk () {
    for element in $1/*; do
      [ -h "$element" -a ! -e "$element" ] && echo \"$element\"
      [ -d "$element" ] && linkchk $element
    # Of course, '-h' tests for symbolic link, '-d' for directory.
    done
}

#  Send each arg that was passed to the script to the linkchk() function
#+ if it is a valid directoy.  If not, then print the error message
#+ and usage info.
##################
for directory in $directorys; do
    if [ -d $directory ]
    then linkchk $directory
    else
        echo "$directory is not a directory"
        echo "Usage: $0 dir1 dir2 ..."
    fi
done

exit $?

Deprecate
...

To pray against, as

Deprecate
...

To pray against, as an evil;
to seek to avert by prayer;
to desire the removal of;
to seek deliverance from;
to express deep regret for;
to disapprove of strongly.

Deprecate
...

To pray against, as an evil;
to seek to avert by prayer;
to desire the removal of;
to seek deliverance from;
to express deep regret for;
to disapprove of strongly.