Conditional Expressions

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每次都會忘記,記錄一下省得每次都要用 Google 找半天

BASH

-a file ~ True if file exists.

-b file ~ True if file exists and is a block special file.

-c file ~ True if file exists and is a character special file.

-d file ~ True if file exists and is a directory.

-e file ~ True if file exists.

-f file ~ True if file exists and is a regular file.

-g file ~ True if file exists and its set-group-id bit is set.

-h file ~ True if file exists and is a symbolic link.

-k file ~ True if file exists and its “sticky” bit is set.

-p file ~ True if file exists and is a named pipe (FIFO).

-r file ~ True if file exists and is readable.

-s file ~ True if file exists and has a size greater than zero.

-t fd ~ True if file descriptor fd is open and refers to a terminal.

-u file ~ True if file exists and its set-user-id bit is set.

-w file ~ True if file exists and is writable.

-x file ~ True if file exists and is executable.

-O file ~ True if file exists and is owned by the effective user id.

-G file ~ True if file exists and is owned by the effective group id.

-L file ~ True if file exists and is a symbolic link.

-S file ~ True if file exists and is a socket.

-N file ~ True if file exists and has been modified since it was last read.

file1 -nt file2 ~ True if file1 is newer (according to modification date) than file2, or if file1 exists and file2 does not.

file1 -ot file2 ~ True if file1 is older than file2, or if file2 exists and file1 does not.

file1 -ef file2 ~ True if file1 and file2 refer to the same device and inode numbers.

-o optname ~ True if shell option optname is enabled. The list of options appears in the description of the -ooption to the set builtin (see The Set Builtin).

-z string ~ True if the length of string is zero.

-n string ~ True if the length of string is non-zero.

string1 == string2 ~ True if the strings are equal. ‘=’ may be used in place of ‘==’ for strict posix compliance.

string1 != string2 ~ True if the strings are not equal.

string1 < string2 ~ True if string1 sorts before string2 lexicographically in the current locale.

string1 > string2 ~ True if string1 sorts after string2 lexicographically in the current locale.

arg1 OP arg2 ~ OP is one of ‘-eq’, ‘-ne’, ‘-lt’, ‘-le’, ‘-gt’, or ‘-ge’. These arithmetic binary operators return true if arg1 is equal to, not equal to, less than, less than or equal to, greater than, or greater than or equal to arg2, respectively. Arg1 and arg2 may be positive or negative integers.

資料來源: http://www.gnu.org/software/bash/manual/bashref.html#Bash-Conditional-Expressions

TCSH

-r   Read access
-w   Write access
-x   Execute access
-X   Executable in the path or shell builtin, e.g., `-X ls' and  `-X
	       ls-F' are generally true, but `-X /bin/ls' is not (+)
-e   Existence
-o   Ownership
-z   Zero size
-s   Non-zero size (+)
-f   Plain file
-d   Directory
-l   Symbolic link (+) *
-b   Block special file (+)
-c   Character special file (+)
-p   Named pipe (fifo) (+) *
-S   Socket special file (+) *
-u   Set-user-ID bit is set (+)
-g   Set-group-ID bit is set (+)
-k   Sticky bit is set (+)
-t   file  (which  must be a digit) is an open file descriptor for a
	       terminal device (+)
-R   Has been migrated (convex only) (+)
-L   Applies subsequent operators in a multiple-operator test  to  a
	       symbolic  link rather than to the file to which the link points
	       (+) *
資料來源 FreeBSD tcsh manual pages

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