getpass(3) 맨 페이지 - 윈디하나의 솔라나라

개요

섹션
맨 페이지 이름
검색(S)

getpass(3)

GETPASS(3)                 Linux Programmer's Manual                GETPASS(3)



NAME
       getpass - get a password

SYNOPSIS
       #include <unistd.h>

       char *getpass(const char *prompt);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       getpass():
           Since glibc 2.2.2:
               _XOPEN_SOURCE && ! (_POSIX_C_SOURCE >= 200112L)
                   || /* Glibc since 2.19: */ _DEFAULT_SOURCE
                   || /* Glibc versions <= 2.19: */ _BSD_SOURCE
           Before glibc 2.2.2:
               none

DESCRIPTION
       This  function  is obsolete.  Do not use it.  If you want to read input
       without terminal echoing enabled, see the description of the ECHO  flag
       in termios(3).

       The  getpass() function opens /dev/tty (the controlling terminal of the
       process), outputs the string prompt, turns off echoing, reads one  line
       (the  "password"),  restores  the  terminal  state  and closes /dev/tty
       again.

RETURN VALUE
       The function getpass() returns a pointer to a static buffer  containing
       (the  first  PASS_MAX  bytes of) the password without the trailing new‐
       line, terminated by a null byte ('\0').  This buffer may be overwritten
       by  a  following call.  On error, the terminal state is restored, errno
       is set appropriately, and NULL is returned.

ERRORS
       The function may fail if

       ENXIO  The process does not have a controlling terminal.

FILES
       /dev/tty

ATTRIBUTES
       For  an  explanation  of  the  terms  used   in   this   section,   see
       attributes(7).

       allbox;  lb  lb  lb  l  l  l.   Interface Attribute Value  T{ getpass()
       T}   Thread safety     MT-Unsafe term

CONFORMING TO
       Present in SUSv2, but marked LEGACY.  Removed in POSIX.1-2001.

NOTES
       In the GNU C library implementation, if /dev/tty cannot be opened,  the
       prompt is written to stderr and the password is read from stdin.  There
       is no limit on the length of the password.  Line editing  is  not  dis‐
       abled.

       According to SUSv2, the value of PASS_MAX must be defined in <limits.h>
       in case it is smaller than 8, and can in any  case  be  obtained  using
       sysconf(_SC_PASS_MAX).    However,   POSIX.2  withdraws  the  constants
       PASS_MAX and _SC_PASS_MAX, and the function getpass().  The glibc  ver‐
       sion accepts _SC_PASS_MAX and returns BUFSIZ (e.g., 8192).

BUGS
       The  calling  process  should  zero the password as soon as possible to
       avoid leaving the cleartext password visible in the  process's  address
       space.

SEE ALSO
       crypt(3)

COLOPHON
       This  page  is  part of release 5.02 of the Linux man-pages project.  A
       description of the project, information about reporting bugs,  and  the
       latest     version     of     this    page,    can    be    found    at
       https://www.kernel.org/doc/man-pages/.



Linux                             2019-03-06                        GETPASS(3)
맨 페이지 내용의 저작권은 맨 페이지 작성자에게 있습니다.
RSS ATOM XHTML 5 CSS3