Linux - help komutu

└─| chmod --help
Usage: chmod [OPTION]... MODE[,MODE]... FILE...
  or:  chmod [OPTION]... OCTAL-MODE FILE...
  or:  chmod [OPTION]... --reference=RFILE FILE...
Change the mode of each FILE to MODE.
With --reference, change the mode of each FILE to that of RFILE.

  -c, --changes          like verbose but report only when a change is made
  -f, --silent, --quiet  suppress most error messages
  -v, --verbose          output a diagnostic for every file processed
      --no-preserve-root  do not treat '/' specially (the default)
      --preserve-root    fail to operate recursively on '/'
      --reference=RFILE  use RFILE's mode instead of MODE values
  -R, --recursive        change files and directories recursively
      --help     display this help and exit
      --version  output version information and exit

Each MODE is of the form '[ugoa]*([-+=]([rwxXst]*|[ugo]))+|[-+=][0-7]+'.

GNU coreutils online help: 
Full documentation 
or available locally via: info '(coreutils) chmod invocation'
┌──(root@taylan)-[~]
└─|

┌──(root@taylan)-[~]
└─| help chmod
bash: help: no help topics match `chmod'.  Try `help help' or `man -k chmod' or `info chmod'.
┌──(root@taylan)-[~]
└─|

┌──(root@taylan)-[~]
└─| echo Merhaba
Merhaba

┌──(root@taylan)-[~]
└─| echo --help
--help

┌──(root@taylan)-[~]
└─| help echo
echo: echo [-neE] [arg ...]
    Write arguments to the standard output.

    Display the ARGs, separated by a single space character and followed by a
    newline, on the standard output.

    Options:
      -n        do not append a newline
      -e        enable interpretation of the following backslash escapes
      -E        explicitly suppress interpretation of backslash escapes

    `echo' interprets the following backslash-escaped characters:
      \a        alert (bell)
      \b        backspace
      \c        suppress further output
      \e        escape character
      \E        escape character
      \f        form feed
      \n        new line
      \r        carriage return
      \t        horizontal tab
      \v        vertical tab
      \\        backslash
      \0nnn     the character whose ASCII code is NNN (octal).  NNN can be
                0 to 3 octal digits
      \xHH      the eight-bit character whose value is HH (hexadecimal).  HH
                can be one or two hex digits
      \uHHHH    the Unicode character whose value is the hexadecimal value HHHH.
                HHHH can be one to four hex digits.
      \UHHHHHHHH the Unicode character whose value is the hexadecimal value
                HHHHHHHH. HHHHHHHH can be one to eight hex digits.

    Exit Status:
    Returns success unless a write error occurs.