18.104.22.168 Unusual Characters in File Names
As discussed above, you often need to be careful about how the names
of files are handled by
find and other programs. If the output
find is not going to another program but instead is being
shown on a terminal, this can still be a problem. For example, some
character sequences can reprogram the function keys on some terminals.
See Security Considerations, for a discussion of other security
problems relating to
Unusual characters are handled differently by various
actions, as described below.
- Always print the exact file name, unchanged, even if the output is
going to a terminal.
- Always print the exact file name, unchanged. This will probably
change in a future release.
- Unusual characters are always escaped. White space, backslash, and
double quote characters are printed using C-style escaping (for
example ‘\f’, ‘\"’). Other unusual characters are printed
using an octal escape. Other printable characters (for ‘-ls’ and
‘-fls’ these are the characters between octal 041 and 0176) are
- If the output is not going to a terminal, it is printed as-is.
Otherwise, the result depends on which directive is in use:
- %D, %F, %H, %Y, %y
- These expand to values which are not under control of files' owners,
and so are printed as-is.
- %a, %b, %c, %d, %g, %G, %i, %k, %m, %M, %n, %s, %t, %u, %U
- These have values which are under the control of files' owners but
which cannot be used to send arbitrary data to the terminal, and so
these are printed as-is.
- %f, %h, %l, %p, %P
- The output of these directives is quoted if the output is going to a
terminal. The setting of the `LC_CTYPE' environment
variable is used to determine which characters need to be quoted.
This quoting is performed in the same way as for GNU
is not the same quoting mechanism as the one used for ‘-ls’ and
‘fls’. If you are able to decide what format to use for the
find then it is normally better to use ‘\0’ as a
terminator than to use newline, as file names can contain white space
and newline characters.
- Quoting is handled in the same way as for the ‘%p’ directive of
‘-printf’ and ‘-fprintf’. If you are using
find in a
script or in a situation where the matched files might have arbitrary
names, you should consider using ‘-print0’ instead of
locate program quotes and escapes unusual characters in
file names in the same way as
find's ‘-print’ action.
The behaviours described above may change soon, as the treatment of
unprintable characters is harmonised for ‘-ls’, ‘-fls’,
‘-print’, ‘-fprint’, ‘-printf’ and ‘-fprintf’.