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Diffstat (limited to 'doc/antora/modules/unlang/pages/xlat/alternation.adoc')
| -rw-r--r-- | doc/antora/modules/unlang/pages/xlat/alternation.adoc | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/doc/antora/modules/unlang/pages/xlat/alternation.adoc b/doc/antora/modules/unlang/pages/xlat/alternation.adoc new file mode 100644 index 0000000..adb7604 --- /dev/null +++ b/doc/antora/modules/unlang/pages/xlat/alternation.adoc @@ -0,0 +1,24 @@ += Alternation Syntax + +Alternation syntax similar to that used in Unix shells may also be +used: + +`%{%{Foo}:-bar}` + +This code returns the value of `%{Foo}`, if it has a value. +Otherwise, it returns a literal string bar. + +`%{%{Foo}:-%{Bar}}` + +This code returns the value of `%{Foo}`, if it has a value. +Otherwise, it returns the expansion of `%{Bar}`. + +These conditional expansions can be nested to almost any depth, such +as with `%{%{One}:-%{%{Two}:-%{Three}}}`. + +.Examples +`%{%{Stripped-User-Name}:-%{User-Name}}` + +`%{%{Framed-IP-Address}:-<none>}` + +// Copyright (C) 2020 Network RADIUS SAS. Licenced under CC-by-NC 4.0. +// Development of this documentation was sponsored by Network RADIUS SAS. |