60 lines
1.9 KiB
C++
60 lines
1.9 KiB
C++
/*******************************************************************************
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Copyright(C) Jonas 'Sortie' Termansen 2013.
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This file is part of the Sortix C Library.
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The Sortix C Library is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation, either version 3 of the License, or (at your
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option) any later version.
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The Sortix C Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
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unistd/getlogin_r.cpp
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Get name of user logged in at the controlling terminal.
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*******************************************************************************/
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#include <errno.h>
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#include <pwd.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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extern "C" int getlogin_r(char* buf, size_t size)
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{
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struct passwd passwd_object;
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struct passwd* passwd;
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int errnum = 0;
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char* pwdbuf = NULL;
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size_t pwdbuflen = 0;
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do
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{
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// TODO: Potential overflow.
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size_t new_pwdbuflen = pwdbuflen ? 2 * pwdbuflen : 64;
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char* new_pwdbuf = (char*) realloc(pwdbuf, new_pwdbuflen);
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if ( !new_pwdbuf )
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return free(pwdbuf), -1;
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pwdbuf = new_pwdbuf;
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pwdbuflen = new_pwdbuflen;
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} while ( (errnum = getpwuid_r(getuid(), &passwd_object, pwdbuf, pwdbuflen,
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&passwd)) == ERANGE );
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if ( errnum )
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return free(pwdbuf), errno = errnum, -1;
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const char* username = passwd->pw_name;
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if ( size <= strlcpy(buf, username, size) )
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return free(pwdbuf), errno = ERANGE, -1;
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free(pwdbuf);
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return 0;
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}
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