find finds files.

find [-PLH] start-location[s] -test-option test-condition -action-option


Options

[-PLH] control handling of symbolic links.

-P  (default), do not follow a symbolic link. Process the link file as a file.
    Assume you have a homepage.html under public_html which is a symbolic link 
      to storge on the babbage system.

    If you log into hopper, and run
    find . -name homepage.htm
    You should get no match. 

-L  Follow the link if it to a directory. Circularly linked names 

    If you log into hopper, and run
    find -L . -name homepage.htm
    You will find a match.

    But can cause problems if link is circular.
    Let say, on hopper, you have managed to symbolically linked dira to dir1 
     and dira to dir1.

    You will get an error/warning :
    find: `./dir1': Too many levels of symbolic links
    find: `./dira': Too many levels of symbolic links

-H Follow link but only if it named as a start-location.



Start point[s] for search

start-location[s] - list of one or more top level directories 
   to seach in.

Search will traverse every child directory under top level directory,
  unless permissions block.
  unless -prune used. 

If no start-location used, current directory . assumed.

If absolute path specified, absolute path will be used in result.

find $HOME -name "*.c"
will generate a list any files with a .c extension. The list will
include the absolute path.



Test condition

-test-option test-condition - determines parameter[s] to use
  to recognize file of interest.


No test condition specified.
Will list all files found. Useful for generating a list of all files with
  path information.


find $HOME


-name name - search for file named.
Wild-cards may be used but need to be quoted.


find . -name "*.c"

Lists all files with .c extension. Path from current directory.


Probably the most common search condtion used.


-inum n - search for all filenames linked to specified inode number.

-iname file-name - search for all filenames linked to same inode as
the specified file-name.

-links  [+/-]n - search for all filenames with a link count more
than n (+n), less than n (-n), or equal to n.

-uid n
-uname user-name

 - search for all files belonging to specified user. Use uid # or name.

-gid n
-group group-name

 - search for all files belonging to specified group. Use gid # or name.

-nouser
-nogroup

 - Looks for files that have an invalid uid or gid.

-size [+/-]n[bcwkMG] - search for file less than (-n), greater than (+n),
or equal to n.

[bcwkMG] - scalar mulitipliers.

c - character
b - 512-byte block
w - two-byte word
k - kilobyte (1024 bytes)
M - Megabyte (1048576 bytes)
G - Gigabytes (2^30 bytes)


-type {bcdprls} - search by filetype.

b - block special
c - character special
d - directory
f - regular - -L and -follow options may change match somewhat.
p - named pipe
l - symbolic link
s - socket


time based tests 

-atime [+/-]n - last time file accessed, scale days.
-amin [+/-]n - last time file accessed, scale minutes.
-ctime [+/-]n - last time status(inode) modified, scale days.
-cmin [+/-]n - last time status(inode) modified, scale minutes.
-mtime [+/-]n - last time file modified, scale days.
-mmin [+/-]n - last time file modified, scale minutes.


-anewer file-name - find files more recently than named file.
-cnewer file-name - find files with status change newer 
    than named file.
-newer file-name - find files newer than named file.
# Use ! to create a "older" search.


-perm mod-values - find files based on various permissions.
Does an exact match if just mod-values listed.
If octal used, need to list all 4 octal values {sST}{rwx}{rwx}{rwx}
find . -perm 0753 # (not suid,guid or sticky), u=rwx, g=rx, o=x
find . -perm u=x,g=w # lists files where only executable for user 
  and writable for group. All other permissions off.

For broader scope, prefix with minus. 

find . -perm -0753 # match as long as user has all permissions, 
  group has at least readable and executable permission
  and other has at least executable permissions.

find . -perm -g=w # lists files that at least have group = write.

To do a type of or where at least one of the user types is on,
  use forward slash.

find . -perm /ugo+w # lists files where write is on for any of the
  user types, user(owner), group, other. Just one or all or any combination.


find . -perm -444 -perm /222 ! -perm /111
find . -perm -a+r -perm /a+w ! -perm /a+x
  # finds files in which every one has read, at least one user-type has write,
  and nobody has executable (note the ! - NOT )


There are several other test conditions. See man find
The man page on find is one of the better man pages on the system.
It includes a whole section of examples.


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