/usr/bin/[ 넌 모니?

도대체 이녀석 정체가 멀까?
도움말 상으로는 test로 연결이 되는데 흐음...
쉘 스크립트에서 사용하는 [] 랑 연관이 있는걸까?

[링크 : http://linux.die.net/man/1/test] 

$ ll -al \[ -rwxr-xr-x 1 root root 42584 2010-09-22 03:33 [*

$ man -k "\[" [ (1)                - check file types and compare values

$ file [ [: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.15, stripped

% ./\[ --help BusyBox v1.14.2 (2011-01-24 14:35:28 KST) multi-call binary Usage: [ EXPRESSION ] Check file types, compare values etc. Return a 0/1 exit code depending on logical value of EXPRESSION

/usr/bin$ ./\[ --help 사용법: test 표현식   또는:  test   또는:  [ 표현식 ]   또는:  [ ]   또는:  [ 옵션 Exit with the status determined by EXPRESSION.       --help     이 도움말을 표시하고 끝냅니다       --version  버전 정보를 출력하고 끝냅니다 An omitted EXPRESSION defaults to false.  Otherwise, EXPRESSION is true or false and sets exit status.  It is one of:   ( EXPRESSION )               EXPRESSION is true   ! EXPRESSION                 EXPRESSION is false   EXPRESSION1 -a EXPRESSION2   both EXPRESSION1 and EXPRESSION2 are true   EXPRESSION1 -o EXPRESSION2   either EXPRESSION1 or EXPRESSION2 is true   -n STRING            the length of STRING is nonzero   STRING               equivalent to -n STRING   -z STRING            the length of STRING is zero   STRING1 = STRING2    the strings are equal   STRING1 != STRING2   the strings are not equal   INTEGER1 -eq INTEGER2   INTEGER1 is equal to INTEGER2   INTEGER1 -ge INTEGER2   INTEGER1 is greater than or equal to INTEGER2   INTEGER1 -gt INTEGER2   INTEGER1 is greater than INTEGER2   INTEGER1 -le INTEGER2   INTEGER1 is less than or equal to INTEGER2   INTEGER1 -lt INTEGER2   INTEGER1 is less than INTEGER2   INTEGER1 -ne INTEGER2   INTEGER1 is not equal to INTEGER2   FILE1 -ef FILE2   FILE1 and FILE2 have the same device and inode numbers   FILE1 -nt FILE2   FILE1 is newer (modification date) than FILE2   FILE1 -ot FILE2   FILE1 is older than FILE2   -b FILE     FILE exists and is block special   -c FILE     FILE exists and is character special   -d FILE     FILE exists and is a directory   -e FILE     FILE exists   -f FILE     FILE exists and is a regular file   -g FILE     FILE exists and is set-group-ID   -G FILE     FILE exists and is owned by the effective group ID   -h FILE     FILE exists and is a symbolic link (same as -L)   -k FILE     FILE exists and has its sticky bit set   -L FILE     FILE exists and is a symbolic link (same as -h)   -O FILE     FILE exists and is owned by the effective user ID   -p FILE     FILE exists and is a named pipe   -r FILE     FILE exists and read permission is granted   -s FILE     FILE exists and has a size greater than zero   -S FILE     FILE exists and is a socket   -t FD       file descriptor FD is opened on a terminal   -u FILE     FILE exists and its set-user-ID bit is set   -w FILE     FILE exists and write permission is granted   -x FILE     FILE exists and execute (or search) permission is granted Except for -h and -L, all FILE-related tests dereference symbolic links. Beware that parentheses need to be escaped (e.g., by backslashes) for shells. INTEGER may also be -l STRING, which evaluates to the length of STRING. NOTE: [ honors the --help and --version options, but test does not. test treats each of those as it treats any other nonempty STRING. NOTE: your shell may have its own version of test and/or [, which usually supersedes the version described here.  Please refer to your shell's documentation for details about the options it supports. Report [ bugs to bug-coreutils@gnu.org GNU coreutils home page: <http://www.gnu.org/software/coreutils/> General help using GNU software: <http://www.gnu.org/gethelp/> Report [ translation bugs to <http://translationproject.org/team/>