test evaluation

File type tests -b file True if file exists and is block special. -c file True if file exists and is character special. -d file True if file exists and is a directory. -f file True if file exists and is a regular file. -h file or -L file True if file exists and is a symbolic link. -p file True if file exists and is a named pipe. -S file True if file exists and is a socket. -T [fd] True if fd is opened on a terminal. If fd is omitted, it defaults to 1 (standard output). Access permission tests -g file True if file exists and is set-group-id. -k file True if file has its ``sticky'' bit set. -r file True if file exists and is readable. -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. File characteristics tests -e file True if file exists -s file True if file exists and has a size greater than zero. file1 -nt file2 True if file1 is newer (according to modification date) than file2. file1 -ot file2 True if file1 is older than file2. file1 -ef file2 True if file1 and file2 have the same device and inode numbers.

String tests -z string True if the length of string is zero. -n string or string True if the length of string is non-zero. string1 = string2 True if the strings are equal. string1 != string2 True if the strings are not equal. Numeric tests arg1 -eq arg2 Arithmetic binary operator that returns true iif arg1 is equal to arg2. arg1 and arg2 may be positive integers, negative integers, or the special expression -l string, which evaluates to the length of string. arg1 -ne arg2 Arithmetic binary operator that returns true iif arg1 is not-equal to arg2. See -eq for args. arg1 -lt arg2 Arithmetic binary operator that returns true iif arg1 is less-than arg2. See -eq for args. arg1 -le arg2 Arithmetic binary operator that returns true iif arg1 is less-than-or-equal than arg2. See -eq for args. arg1 -gt arg2 Arithmetic binary operator that returns true iif arg1 is greater-than arg2. See -eq for args. arg1 -ge arg2 Arithmetic binary operator that returns true iif arg1 is greater-than-or-equal than arg2. See -eq for args. Connectives for test ! expr True if expr is false. expr1 -a expr2 True if both expr1 and expr2 are true. expr1 -o expr2 True if either expr1 or expr2 is true.