env.3

linux下qmail的源码 本人加了一些注释

.TH env 3
.SH NAME
env \- manage the environment
.SH SYNTAX
.B #include <env.h>

char **\fBenviron\fP;

char *\fBenv_get\fP(\fIname\fR);
.br
char *\fBenv_pick\fP();

char *\fIname\fR;
.SH DESCRIPTION
The environment,
.BR environ ,
is a 0-terminated array of 0-terminated strings,
called environment variables.
Each environment variable is of the form
.IR name\fB=\fIvalue .

.B env_get
returns the value of the first variable whose name is
.IR name ,
or 0 if there is no such variable.

.B env_pick
returns any variable in the environment,
or 0 if the environment is empty.
.SH "SEE ALSO"
environ(7)