[PATCH 08/14] Better documentation of the environment mechanism

From: Bastien Roucariès <[email protected]>

Compare with argc/argv and describe the purpose of environment
---
 man7/environ.7 | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/man7/environ.7 b/man7/environ.7
index bba4f93cb..2fdb63d68 100644
--- a/man7/environ.7
+++ b/man7/environ.7
@@ -66,6 +66,29 @@ if the
 feature test macro is defined (see
 .BR feature_test_macros(7)).
 .PP
+At time of execution, a program receive context information by two mechanisms. The first way is
+the program arguments, represented by the arguments of
+.I main
+function,
+.I argc
+and
+.I argv
+variables. The second way, is the
+.I environ
+variable as discuted in this manual.
+.PP
+The program arguments are typically used to pass so-called command-line argument specific to
+a particular use of the program being invoked, thus changing the program behavior to an use case.
+The environment, on the other hand, keeps track of information that is shared by many programs and
+rarely changes. For example, a running process can query the value of the
+.B TEMP
+environment variable to discover a suitable location to store temporary files.
+.PP
+Standard environment variables are used for information about the user’s home directory,
+current language,... An user can define additional variables for other purposes.
+The set of all environment variables that have values is collectively known as
+the process environment or simply the environment.
+.PP
 This array of strings is made available to the process by the
 .BR exec (3)
 call that started the process.