diff options
Diffstat (limited to 'man3/getenv.3')
| -rw-r--r-- | man3/getenv.3 | 144 |
1 files changed, 0 insertions, 144 deletions
diff --git a/man3/getenv.3 b/man3/getenv.3 deleted file mode 100644 index edf7d9ec8..000000000 --- a/man3/getenv.3 +++ /dev/null @@ -1,144 +0,0 @@ -'\" t -.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) -.\" and Copyright (C) 2007, 2012 Michael Kerrisk <mtk.manpages@gmail.com> -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.\" References consulted: -.\" Linux libc source code -.\" Lewine's "POSIX Programmer's Guide" (O'Reilly & Associates, 1991) -.\" 386BSD man pages -.\" Modified Sat Jul 24 19:30:29 1993 by Rik Faith (faith@cs.unc.edu) -.\" Modified Fri Feb 14 21:47:50 1997 by Andries Brouwer (aeb@cwi.nl) -.\" -.TH getenv 3 (date) "Linux man-pages (unreleased)" -.SH NAME -getenv, secure_getenv \- get an environment variable -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.B #include <stdlib.h> -.PP -.BI "char *getenv(const char *" name ); -.BI "char *secure_getenv(const char *" name ); -.fi -.PP -.RS -4 -Feature Test Macro Requirements for glibc (see -.BR feature_test_macros (7)): -.RE -.PP -.BR secure_getenv (): -.nf - _GNU_SOURCE -.fi -.SH DESCRIPTION -The -.BR getenv () -function searches the environment list to find the -environment variable -.IR name , -and returns a pointer to the corresponding -.I value -string. -.PP -The GNU-specific -.BR secure_getenv () -function is just like -.BR getenv () -except that it returns NULL in cases where "secure execution" is required. -Secure execution is required if one of the following conditions -was true when the program run by the calling process was loaded: -.IP \[bu] 3 -the process's effective user ID did not match its real user ID or -the process's effective group ID did not match its real group ID -(typically this is the result of executing a set-user-ID or -set-group-ID program); -.IP \[bu] -the effective capability bit was set on the executable file; or -.IP \[bu] -the process has a nonempty permitted capability set. -.PP -Secure execution may also be required if triggered -by some Linux security modules. -.PP -The -.BR secure_getenv () -function is intended for use in general-purpose libraries -to avoid vulnerabilities that could occur if -set-user-ID or set-group-ID programs accidentally -trusted the environment. -.SH RETURN VALUE -The -.BR getenv () -function returns a pointer to the value in the -environment, or NULL if there is no match. -.SH ATTRIBUTES -For an explanation of the terms used in this section, see -.BR attributes (7). -.ad l -.nh -.TS -allbox; -lbx lb lb -l l l. -Interface Attribute Value -T{ -.BR getenv (), -.BR secure_getenv () -T} Thread safety MT-Safe env -.TE -.hy -.ad -.sp 1 -.SH STANDARDS -.TP -.BR getenv () -C11, POSIX.1-2008. -.TP -.BR secure_getenv () -GNU. -.SH HISTORY -.TP -.BR getenv () -POSIX.1-2001, C89, C99, SVr4, 4.3BSD. -.TP -.BR secure_getenv () -glibc 2.17. -.SH NOTES -The strings in the environment list are of the form \fIname=value\fP. -.PP -As typically implemented, -.BR getenv () -returns a pointer to a string within the environment list. -The caller must take care not to modify this string, -since that would change the environment of the process. -.PP -The implementation of -.BR getenv () -is not required to be reentrant. -The string pointed to by the return value of -.BR getenv () -may be statically allocated, -and can be modified by a subsequent call to -.BR getenv (), -.BR putenv (3), -.BR setenv (3), -or -.BR unsetenv (3). -.PP -The "secure execution" mode of -.BR secure_getenv () -is controlled by the -.B AT_SECURE -flag contained in the auxiliary vector passed from the kernel to user space. -.SH SEE ALSO -.BR clearenv (3), -.BR getauxval (3), -.BR putenv (3), -.BR setenv (3), -.BR unsetenv (3), -.BR capabilities (7), -.BR environ (7) |