diff options
Diffstat (limited to 'make.texinfo')
| -rw-r--r-- | make.texinfo | 37 |
1 files changed, 31 insertions, 6 deletions
diff --git a/make.texinfo b/make.texinfo index 8e8c1cb..9994f13 100644 --- a/make.texinfo +++ b/make.texinfo @@ -19,7 +19,7 @@ automatically which pieces of a large program need to be recompiled, and issues the commands to recompile them. @c !!set edition, date, version -This is Edition 0.33 Beta, last updated 3 May 1992, +This is Edition 0.33 Beta, last updated 4 May 1992, of @cite{The GNU Make Manual}, for @code{make}, Version 3.63 Beta. Copyright (C) 1988, 1989, 1990, 1991, 1992 Free Software Foundation, Inc. @@ -94,7 +94,7 @@ large program need to be recompiled, and issues the commands to recompile them.@refill This is Edition 0.33 Beta of the @cite{GNU Make Manual}, -last updated 3 May 1992, +last updated 4 May 1992, for @code{make} Version 3.63 Beta.@refill This manual describes @code{make} and contains the following chapters:@refill @@ -2491,10 +2491,10 @@ the sub-@code{make} as defaults, but do not override what is specified in the sub-@code{make}'s makefile unless the @samp{-e} switch is used (@pxref{Options Summary, ,Summary of Options}).@refill -By default, a variable is passed down if its name consists only of letters, -numbers and underscores. Some shells cannot cope with environment -variable names consisting of characters other than letters, numbers, -and underscores. +By default, a variable is only passed down if its name consists only of +letters, numbers and underscores. Some shells cannot cope with +environment variable names consisting of characters other than letters, +numbers, and underscores. Variable are @emph{not} normally passed down if they were created by default by @code{make} (@pxref{Implicit Variables, ,Variables Used by @@ -2550,6 +2550,31 @@ export @var{variable} You may notice that the @code{export} and @code{unexport} directives work in @code{make} just like they work in the shell, @code{sh}. +If you want all variables to be exported by default, you can use +@code{export} by itself: + +@example +export +@end example + +@noindent +This tells @code{make} that variables which are not explicitly mentioned +in an @code{export} or @code{unexport} directive should be exported. +Any variable given in an @code{unexport} directive will still @emph{not} +be exported. If you use @code{export} by itself to export variables by +default, variables whose names contain characters other than +alphanumerics and underscores will not be exported unless specifically +mentioned in an @code{export} directive.@refill + +Likewise, you can use @code{unexport} by itself to tell @code{make} +@emph{not} to export variables by default. Since this is the default +behavior, you would only need to do this if @code{export} had been used +by itself earlier (in an included makefile, perhaps). You +@strong{cannot} use @code{export} and @code{unexport} by themselves to +have variables exported for some commands and not for others. The last +@code{export} or @code{unexport} directive that appears by itself +determines the behavior for the entire run of @code{make}.@refill + @vindex MAKELEVEL As a special feature, the variable @code{MAKELEVEL} is changed when it is passed down from level to level. This variable's value is a string |