adds
.I inc
to the nice value for the calling process.
-(A large nice value means a low priority.)
-Only the super\%user may specify a negative increment, or priority increase.
+(A higher nice value means a low priority.)
+Only the super\%user may specify a negative increment,
+or priority increase.
The range for nice values is described in
.BR getpriority (2).
.SH "RETURN VALUE"
.BR fork (),
except that the behaviour is undefined if the process created by
.BR vfork ()
-either modifies any data other than a variable of type pid_t used
-to store the return value from
+either modifies any data other than a variable of type
+.I pid_t
+used to store the return value from
.BR vfork (),
or returns from the function in which
.BR vfork ()
or one of the
.BR exec ()
family of functions.
-.SH ERRORS
-.TP
-.B EAGAIN
-Too many processes; try again.
-.TP
-.B ENOMEM
-There is insufficient swap space for the new process.
.SH "LINUX DESCRIPTION"
.BR vfork (),
just like
.BR _exit ().
.PP
Signal handlers are inherited, but not shared. Signals to the parent
-arrive after the child releases the parent.
+arrive after the child releases the parent's memory.
.SH "HISTORIC DESCRIPTION"
Under Linux,
.BR fork ()