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Diffstat (limited to 'doc/guix.texi')
| -rw-r--r-- | doc/guix.texi | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index 96b4675a01..32e34b7d52 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -41007,13 +41007,15 @@ The easiest way to extend a service type, without defining a new service type is to use the @code{simple-service} helper from @code{(gnu services)}. +@findex literal-string @lisp (simple-service 'some-useful-env-vars-service home-environment-variables-service-type `(("LESSHISTFILE" . "$XDG_CACHE_HOME/.lesshst") ("SHELL" . ,(file-append zsh "/bin/zsh")) ("USELESS_VAR" . #f) - ("_JAVA_AWT_WM_NONREPARENTING" . #t))) + ("_JAVA_AWT_WM_NONREPARENTING" . #t) + ("LITERAL_VALUE" . ,(literal-string "$@{abc@}")))) @end lisp If you include such a service in you home environment definition, it @@ -41021,11 +41023,17 @@ will add the following content to the @file{setup-environment} script (which is expected to be sourced by the login shell): @example -export LESSHISTFILE=$XDG_CACHE_HOME/.lesshst -export SHELL=/gnu/store/2hsg15n644f0glrcbkb1kqknmmqdar03-zsh-5.8/bin/zsh +export LESSHISTFILE="$XDG_CACHE_HOME/.lesshst" +export SHELL="/gnu/store/2hsg15n644f0glrcbkb1kqknmmqdar03-zsh-5.8/bin/zsh" export _JAVA_AWT_WM_NONREPARENTING +export LITERAL_VALUE='$@{abc@}' @end example +Notice that @code{literal-string} above lets us declare that a value is +to be interpreted as a @dfn{literal string}, meaning that ``special +characters'' such as the dollar sign will not be interpreted by the +shell. + @quotation Note Make sure that module @code{(gnu packages shells)} is imported with @code{use-modules} or any other way, this namespace contains the |