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| author | Alejandro Colomar <alx.manpages@gmail.com> | 2022-09-09 14:15:08 +0200 |
|---|---|---|
| committer | Alejandro Colomar <alx.manpages@gmail.com> | 2022-09-09 14:15:08 +0200 |
| commit | 96e72ec1fbadd13cbcbc2b263540e4f5e9e09d7c (patch) | |
| tree | 70686b943e33a6e939ad265acb7ddfef70b91f32 /man/man3/getlogin.3 | |
| parent | 8f4ed6463206e8ede815c72085c7305dafc2e4fc (diff) | |
| download | man-pages-96e72ec1fbadd13cbcbc2b263540e4f5e9e09d7c.tar.gz | |
Revert "src.mk, All pages: Move man* to man/"
This reverts commit 70ac1c4785fc1e158ab2349a962dba2526bf4fbc.
Link: <https://lore.kernel.org/linux-man/YxcV4h+Xn7cd6+q2@pevik/T/>
Reported-by: Petr Vorel <pvorel@suse.cz>
Reported-by: Jakub Wilk <jwilk@jwilk.net>
Cc: Stefan Puiu <stefan.puiu@gmail.com>
Signed-off-by: Alex Colomar <alx.manpages@gmail.com>
Diffstat (limited to 'man/man3/getlogin.3')
| -rw-r--r-- | man/man3/getlogin.3 | 239 |
1 files changed, 0 insertions, 239 deletions
diff --git a/man/man3/getlogin.3 b/man/man3/getlogin.3 deleted file mode 100644 index 50b8b008bd..0000000000 --- a/man/man3/getlogin.3 +++ /dev/null @@ -1,239 +0,0 @@ -.\" Copyright 1995 James R. Van Zandt <jrv@vanzandt.mv.com> -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.\" Changed Tue Sep 19 01:49:29 1995, aeb: moved from man2 to man3 -.\" added ref to /etc/utmp, added BUGS section, etc. -.\" modified 2003 Walter Harms, aeb - added getlogin_r, note on stdin use -.TH GETLOGIN 3 2021-03-22 "Linux man-pages (unreleased)" -.SH NAME -getlogin, getlogin_r, cuserid \- get username -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.B #include <unistd.h> -.PP -.B "char *getlogin(void);" -.BI "int getlogin_r(char *" buf ", size_t " bufsize ); -.PP -.B #include <stdio.h> -.PP -.BI "char *cuserid(char *" string ); -.fi -.PP -.RS -4 -Feature Test Macro Requirements for glibc (see -.BR feature_test_macros (7)): -.RE -.PP -.BR getlogin_r (): -.nf -.\" Deprecated: _REENTRANT || - _POSIX_C_SOURCE >= 199506L -.fi -.PP -.BR cuserid (): -.nf - Since glibc 2.24: - (_XOPEN_SOURCE && ! (_POSIX_C_SOURCE >= 200112L) - || _GNU_SOURCE - Up to and including glibc 2.23: - _XOPEN_SOURCE -.fi -.SH DESCRIPTION -.BR getlogin () -returns a pointer to a string containing the name of -the user logged in on the controlling terminal of the process, or a -null pointer if this information cannot be determined. -The string is -statically allocated and might be overwritten on subsequent calls to -this function or to -.BR cuserid (). -.PP -.BR getlogin_r () -returns this same username in the array -.I buf -of size -.IR bufsize . -.PP -.BR cuserid () -returns a pointer to a string containing a username -associated with the effective user ID of the process. -If \fIstring\fP -is not a null pointer, it should be an array that can hold at least -\fBL_cuserid\fP characters; the string is returned in this array. -Otherwise, a pointer to a string in a static area is returned. -This -string is statically allocated and might be overwritten on subsequent -calls to this function or to -.BR getlogin (). -.PP -The macro \fBL_cuserid\fP is an integer constant that indicates how -long an array you might need to store a username. -\fBL_cuserid\fP is declared in \fI<stdio.h>\fP. -.PP -These functions let your program identify positively the user who is -running -.RB ( cuserid ()) -or the user who logged in this session -.RB ( getlogin ()). -(These can differ when set-user-ID programs are involved.) -.PP -For most purposes, it is more useful to use the environment variable -\fBLOGNAME\fP to find out who the user is. -This is more flexible -precisely because the user can set \fBLOGNAME\fP arbitrarily. -.SH RETURN VALUE -.BR getlogin () -returns a pointer to the username when successful, -and NULL on failure, with -.I errno -set to indicate the error. -.BR getlogin_r () -returns 0 when successful, and nonzero on failure. -.SH ERRORS -POSIX specifies: -.TP -.B EMFILE -The per-process limit on the number of open file descriptors has been reached. -.TP -.B ENFILE -The system-wide limit on the total number of open files has been reached. -.TP -.B ENXIO -The calling process has no controlling terminal. -.TP -.B ERANGE -(getlogin_r) -The length of the username, including the terminating null byte (\(aq\e0\(aq), -is larger than -.IR bufsize . -.PP -Linux/glibc also has: -.TP -.B ENOENT -There was no corresponding entry in the utmp-file. -.TP -.B ENOMEM -Insufficient memory to allocate passwd structure. -.TP -.B ENOTTY -Standard input didn't refer to a terminal. -(See BUGS.) -.SH FILES -.TP -\fI/etc/passwd\fP -password database file -.TP -\fI/var/run/utmp\fP -(traditionally \fI/etc/utmp\fP; -some libc versions used \fI/var/adm/utmp\fP) -.SH ATTRIBUTES -For an explanation of the terms used in this section, see -.BR attributes (7). -.ad l -.nh -.TS -allbox; -lb lb lbx -l l l. -Interface Attribute Value -T{ -.BR getlogin () -T} Thread safety T{ -MT-Unsafe race:getlogin race:utent -sig:ALRM timer locale -T} -T{ -.BR getlogin_r () -T} Thread safety T{ -MT-Unsafe race:utent sig:ALRM timer -locale -T} -T{ -.BR cuserid () -T} Thread safety T{ -MT-Unsafe race:cuserid/!string locale -T} -.TE -.hy -.ad -.sp 1 -In the above table, -.I utent -in -.I race:utent -signifies that if any of the functions -.BR setutent (3), -.BR getutent (3), -or -.BR endutent (3) -are used in parallel in different threads of a program, -then data races could occur. -.BR getlogin () -and -.BR getlogin_r () -call those functions, -so we use race:utent to remind users. -.SH STANDARDS -.BR getlogin () -and -.BR getlogin_r (): -POSIX.1-2001, POSIX.1-2008. -.PP -System V has a -.BR cuserid () -function which uses the real -user ID rather than the effective user ID. -The -.BR cuserid () -function -was included in the 1988 version of POSIX, -but removed from the 1990 version. -It was present in SUSv2, but removed in POSIX.1-2001. -.PP -OpenBSD has -.BR getlogin () -and -.BR setlogin (), -and a username -associated with a session, even if it has no controlling terminal. -.SH BUGS -Unfortunately, it is often rather easy to fool -.BR getlogin (). -Sometimes it does not work at all, because some program messed up -the utmp file. -Often, it gives only the first 8 characters of -the login name. -The user currently logged in on the controlling terminal -of our program need not be the user who started it. -Avoid -.BR getlogin () -for security-related purposes. -.PP -Note that glibc does not follow the POSIX specification and uses -.I stdin -instead of -.IR /dev/tty . -A bug. -(Other recent systems, like SunOS 5.8 and HP-UX 11.11 and FreeBSD 4.8 -all return the login name also when -.I stdin -is redirected.) -.PP -Nobody knows precisely what -.BR cuserid () -does; avoid it in portable programs. -Or avoid it altogether: use -.I getpwuid(geteuid()) -instead, if that is -what you meant. -.B Do not use -.BR cuserid (). -.SH SEE ALSO -.BR logname (1), -.BR geteuid (2), -.BR getuid (2), -.BR utmp (5) |