| Message ID | 20221226181938.30003-1-ludo@gnu.org |
|---|---|
| State | New |
| Headers | show |
| Series | [bug#60341,Home] home: services: environment-variables: Add support for literal strings. | expand |
On 2022-12-26 19:19, Ludovic Courtès wrote: > * gnu/home/services.scm (<literal-string>): New record type. > (environment-variable-shell-definitions): Split 'shell-quote' into > 'quote-string' and 'shell-double-quote'. Add 'shell-single-quote'. > Add clause for 'literal-string' records. > * tests/guix-home.sh: Test it. > * doc/guix.texi (Essential Home Services): Document it. > --- > doc/guix.texi | 14 ++++++++++--- > gnu/home/services.scm | 48 ++++++++++++++++++++++++++++++++----------- > tests/guix-home.sh | 4 +++- > 3 files changed, 50 insertions(+), 16 deletions(-) > > Hi! > > I found that it’s occasionally useful to be able to define shell variables > with a value that is to be taken literally, without shell expansion. This > is what this patch implements. > > Thoughts? Hi Ludo, the code looks good. I'm a little conserned that one need to learn a new abstraction to properly quote the expression instead of just using " or ' inside value string, but we already have af4c103595a725194318f40fc5aba110772ff417 and with the current state of the code this change looks rational and idiomatic. Also, it makes the interface more high-level, which can be good in some circumstances. > > Ludo’. > > diff --git a/doc/guix.texi b/doc/guix.texi > index efd281d9b0..44361b481a 100644 > --- a/doc/guix.texi > +++ b/doc/guix.texi > @@ -40972,13 +40972,15 @@ 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 > @@ -40986,11 +40988,17 @@ 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 > diff --git a/gnu/home/services.scm b/gnu/home/services.scm > index 99035686f1..2c1f58fddf 100644 > --- a/gnu/home/services.scm > +++ b/gnu/home/services.scm > @@ -1,6 +1,7 @@ > ;;; GNU Guix --- Functional package management for GNU > ;;; Copyright © 2021 Andrew Tropin <andrew@trop.in> > ;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz> > +;;; Copyright © 2022 Ludovic Courtès <ludo@gnu.org> > ;;; > ;;; This file is part of GNU Guix. > ;;; > @@ -33,6 +34,7 @@ (define-module (gnu home services) > #:use-module (guix i18n) > #:use-module (guix modules) > #:use-module (srfi srfi-1) > + #:use-module (srfi srfi-9) > #:use-module (ice-9 match) > #:use-module (ice-9 vlist) > > @@ -47,6 +49,10 @@ (define-module (gnu home services) > home-run-on-change-service-type > home-provenance-service-type > > + literal-string > + literal-string? > + literal-string-value > + > environment-variable-shell-definitions > home-files-directory > xdg-configuration-files-directory > @@ -171,32 +177,50 @@ (define home-profile-service-type > configuration files that the user has declared in their > @code{home-environment} record."))) > > +;; Representation of a literal string. > +(define-record-type <literal-string> > + (literal-string str) > + literal-string? > + (str literal-string-value)) > + > (define (environment-variable-shell-definitions variables) > "Return a gexp that evaluates to a list of POSIX shell statements defining > VARIABLES, a list of environment variable name/value pairs. The returned code > ensures variable values are properly quoted." > - #~(let ((shell-quote > - (lambda (value) > - ;; Double-quote VALUE, leaving dollar sign as is. > - (let ((quoted (list->string > - (string-fold-right > + #~(let* ((quote-string > + (lambda (value quoted-chars) > + (list->string (string-fold-right > (lambda (chr lst) > - (case chr > - ((#\" #\\) > - (append (list chr #\\) lst)) > - (else (cons chr lst)))) > + (if (memq chr quoted-chars) > + (append (list chr #\\) lst) > + (cons chr lst))) > '() > value)))) > - (string-append "\"" quoted "\""))))) > + (shell-double-quote > + (lambda (value) > + ;; Double-quote VALUE, leaving dollar sign as is. > + (string-append "\"" (quote-string value '(#\" #\\)) > + "\""))) > + (shell-single-quote > + (lambda (value) > + ;; Single-quote VALUE to enter a literal string. > + (string-append "'" (quote-string value '(#\' #\\)) > + "'")))) > (string-append > #$@(map (match-lambda > ((key . #f) > "") > ((key . #t) > #~(string-append "export " #$key "\n")) > - ((key . value) > + ((key . (? string? value)) > #~(string-append "export " #$key "=" > - (shell-quote #$value) "\n"))) > + (shell-double-quote #$value) > + "\n")) > + ((key . (? literal-string? value)) > + #~(string-append "export " #$key "=" > + (shell-single-quote > + #$(literal-string-value value)) > + "\n"))) > variables)))) > > (define (environment-variables->setup-environment-script vars) > diff --git a/tests/guix-home.sh b/tests/guix-home.sh > index d5e2dadbb5..423ebf6f33 100644 > --- a/tests/guix-home.sh > +++ b/tests/guix-home.sh > @@ -81,7 +81,8 @@ trap 'chmod -Rf +w "$test_directory"; rm -rf "$test_directory"' EXIT > > (simple-service 'add-environment-variable > home-environment-variables-service-type > - '(("TODAY" . "26 messidor"))) > + `(("TODAY" . "26 messidor") > + ("LITERAL" . ,(literal-string "${abc}")))) > > (simple-service 'home-bash-service-extension-test > home-bash-service-type > @@ -149,6 +150,7 @@ EOF > grep -q "the content of ~/.config/test.conf" "${HOME}/.config/test.conf" > grep '^export PS1="\$GUIX_ENVIRONMENT λ "$' "${HOME}/.bash_profile" > ( . "${HOME}/.guix-home/setup-environment"; test "$TODAY" = "26 messidor" ) > + ( . "${HOME}/.guix-home/setup-environment"; test "$LITERAL" = '${abc}' ) > > # This one should still be here. > grep "stay around" "$HOME/.config/random-file" > > base-commit: 9369c1ccf47d9bf6f2e28a9454c1c329a2044f19
Hi, Andrew Tropin <andrew@trop.in> skribis: > On 2022-12-26 19:19, Ludovic Courtès wrote: [...] >> I found that it’s occasionally useful to be able to define shell variables >> with a value that is to be taken literally, without shell expansion. This >> is what this patch implements. >> >> Thoughts? > > Hi Ludo, > > the code looks good. > > I'm a little conserned that one need to learn a new abstraction to > properly quote the expression instead of just using " or ' inside value > string, but we already have af4c103595a725194318f40fc5aba110772ff417 and > with the current state of the code this change looks rational and > idiomatic. Also, it makes the interface more high-level, which can be > good in some circumstances. Yeah, the shell/Scheme mixture is a bit weird; it’s sort of in-between because you can’t completely ignore that it’s shell code under the hood. Looking at <https://issues.guix.gnu.org/54469>, I think we should strive to not generate non-working shell snippets. Automatic quoting and this ‘literal-string’ construct are a way to achieve that. Ludo’.
On 2023-01-03 23:52, Ludovic Courtès wrote: > Hi, > > Andrew Tropin <andrew@trop.in> skribis: > >> On 2022-12-26 19:19, Ludovic Courtès wrote: > > [...] > >>> I found that it’s occasionally useful to be able to define shell variables >>> with a value that is to be taken literally, without shell expansion. This >>> is what this patch implements. >>> >>> Thoughts? >> >> Hi Ludo, >> >> the code looks good. >> >> I'm a little conserned that one need to learn a new abstraction to >> properly quote the expression instead of just using " or ' inside value >> string, but we already have af4c103595a725194318f40fc5aba110772ff417 and >> with the current state of the code this change looks rational and >> idiomatic. Also, it makes the interface more high-level, which can be >> good in some circumstances. > > Yeah, the shell/Scheme mixture is a bit weird; it’s sort of in-between > because you can’t completely ignore that it’s shell code under the hood. > > Looking at <https://issues.guix.gnu.org/54469>, I think we should strive > to not generate non-working shell snippets. Automatic quoting and this > ‘literal-string’ construct are a way to achieve that. Yep, I think this is a way to go.
Andrew Tropin <andrew@trop.in> skribis: > On 2023-01-03 23:52, Ludovic Courtès wrote: [...] >> Yeah, the shell/Scheme mixture is a bit weird; it’s sort of in-between >> because you can’t completely ignore that it’s shell code under the hood. >> >> Looking at <https://issues.guix.gnu.org/54469>, I think we should strive >> to not generate non-working shell snippets. Automatic quoting and this >> ‘literal-string’ construct are a way to achieve that. > > Yep, I think this is a way to go. Alright, pushed as 73684dc90e013f2f0cca1097b0c944bb9aa88709. Thanks! Ludo’.
I always knew my `environment-variables` were a mess. This patch broke my guix home config and send me down a confusing rabbit hole to this submission. My environment-variables form looks so nice now ;P
diff --git a/doc/guix.texi b/doc/guix.texi index efd281d9b0..44361b481a 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -40972,13 +40972,15 @@ 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 @@ -40986,11 +40988,17 @@ 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 diff --git a/gnu/home/services.scm b/gnu/home/services.scm index 99035686f1..2c1f58fddf 100644 --- a/gnu/home/services.scm +++ b/gnu/home/services.scm @@ -1,6 +1,7 @@ ;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2021 Andrew Tropin <andrew@trop.in> ;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz> +;;; Copyright © 2022 Ludovic Courtès <ludo@gnu.org> ;;; ;;; This file is part of GNU Guix. ;;; @@ -33,6 +34,7 @@ (define-module (gnu home services) #:use-module (guix i18n) #:use-module (guix modules) #:use-module (srfi srfi-1) + #:use-module (srfi srfi-9) #:use-module (ice-9 match) #:use-module (ice-9 vlist) @@ -47,6 +49,10 @@ (define-module (gnu home services) home-run-on-change-service-type home-provenance-service-type + literal-string + literal-string? + literal-string-value + environment-variable-shell-definitions home-files-directory xdg-configuration-files-directory @@ -171,32 +177,50 @@ (define home-profile-service-type configuration files that the user has declared in their @code{home-environment} record."))) +;; Representation of a literal string. +(define-record-type <literal-string> + (literal-string str) + literal-string? + (str literal-string-value)) + (define (environment-variable-shell-definitions variables) "Return a gexp that evaluates to a list of POSIX shell statements defining VARIABLES, a list of environment variable name/value pairs. The returned code ensures variable values are properly quoted." - #~(let ((shell-quote - (lambda (value) - ;; Double-quote VALUE, leaving dollar sign as is. - (let ((quoted (list->string - (string-fold-right + #~(let* ((quote-string + (lambda (value quoted-chars) + (list->string (string-fold-right (lambda (chr lst) - (case chr - ((#\" #\\) - (append (list chr #\\) lst)) - (else (cons chr lst)))) + (if (memq chr quoted-chars) + (append (list chr #\\) lst) + (cons chr lst))) '() value)))) - (string-append "\"" quoted "\""))))) + (shell-double-quote + (lambda (value) + ;; Double-quote VALUE, leaving dollar sign as is. + (string-append "\"" (quote-string value '(#\" #\\)) + "\""))) + (shell-single-quote + (lambda (value) + ;; Single-quote VALUE to enter a literal string. + (string-append "'" (quote-string value '(#\' #\\)) + "'")))) (string-append #$@(map (match-lambda ((key . #f) "") ((key . #t) #~(string-append "export " #$key "\n")) - ((key . value) + ((key . (? string? value)) #~(string-append "export " #$key "=" - (shell-quote #$value) "\n"))) + (shell-double-quote #$value) + "\n")) + ((key . (? literal-string? value)) + #~(string-append "export " #$key "=" + (shell-single-quote + #$(literal-string-value value)) + "\n"))) variables)))) (define (environment-variables->setup-environment-script vars) diff --git a/tests/guix-home.sh b/tests/guix-home.sh index d5e2dadbb5..423ebf6f33 100644 --- a/tests/guix-home.sh +++ b/tests/guix-home.sh @@ -81,7 +81,8 @@ trap 'chmod -Rf +w "$test_directory"; rm -rf "$test_directory"' EXIT (simple-service 'add-environment-variable home-environment-variables-service-type - '(("TODAY" . "26 messidor"))) + `(("TODAY" . "26 messidor") + ("LITERAL" . ,(literal-string "${abc}")))) (simple-service 'home-bash-service-extension-test home-bash-service-type @@ -149,6 +150,7 @@ EOF grep -q "the content of ~/.config/test.conf" "${HOME}/.config/test.conf" grep '^export PS1="\$GUIX_ENVIRONMENT λ "$' "${HOME}/.bash_profile" ( . "${HOME}/.guix-home/setup-environment"; test "$TODAY" = "26 messidor" ) + ( . "${HOME}/.guix-home/setup-environment"; test "$LITERAL" = '${abc}' ) # This one should still be here. grep "stay around" "$HOME/.config/random-file"