From: Bastien Roucariès <ro...@debian.org> Use feature_test_macros and document that historically you should manually declare it. --- man7/environ.7 | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-)
diff --git a/man7/environ.7 b/man7/environ.7 index 981038ea1..7eeb1fe0e 100644 --- a/man7/environ.7 +++ b/man7/environ.7 @@ -36,19 +36,36 @@ environ \- user environment .SH SYNOPSIS .nf +.B #include <unistd.h> +.PP .BI "extern char **" environ ; .fi +.PP +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.PP +.I environ: +.nf + _GNU_SOURCE +.fi .SH DESCRIPTION The variable .I environ points to an array of pointers to strings called the "environment". The last pointer in this array has the value NULL. -(This variable must be declared in the user program, -but is declared in the header file +.PP +Historically and by standard, this variable must be declared in the user program, +but for programmer convenience +.I environ +is also declared in the header file .I <unistd.h> if the .B _GNU_SOURCE -feature test macro is defined.) +feature test macro is defined (see +.BR feature_test_macros(7)). +.PP This array of strings is made available to the process by the .BR exec (3) call that started the process. @@ -380,6 +397,7 @@ should use instead an explicit \(aq\fB.\fP\(aq. .BR putenv (3), .BR setenv (3), .BR unsetenv (3), +.NR feature_test_macros(7), .BR locale (7), .BR ld.so (8), .BR pam_env (8) -- 2.29.2
