Improve documentation regarding Posix utilities

[Shushe] / GNUmakefile

diff --git a/GNUmakefile b/GNUmakefile
index 00b04f2df874acc4a2b517076d9479c973c27687..ba4df950d2927fbd25c997d39765a58b280ccdf5 100644 (file)
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -203,12 +203,12 @@ XMLTYPES := application/xml text/xml +xml
 ifdef GIT
 ifneq ($(wildcard $(THISDIR)/.git),)
 # A description of the current git revision of ⛩️📰 书社.
-THISREV := $(shell $(CD) $(THISDIR); $(GIT) describe 2> /dev/null || $(GIT) rev-parse HEAD 2> /dev/null || true)
+THISREV := $(shell $(CD) $(THISDIR); $(GIT) describe 2> /dev/null || $(GIT) rev-parse HEAD 2> /dev/null || :)
 endif
 
 ifneq ($(wildcard .git),)
 # A description of the current git revision of the working directory.
-SRCREV := $(shell $(GIT) describe 2> /dev/null || $(GIT) rev-parse HEAD 2> /dev/null || true)
+SRCREV := $(shell $(GIT) describe 2> /dev/null || $(GIT) rev-parse HEAD 2> /dev/null || :)
 endif
 endif
 
@@ -233,6 +233,12 @@ VERBOSE :=
 # The default target for this makefile.
 .DEFAULT_GOAL := all
 
+# Flags for use when calling the shell.
+#
+# `-e` enables early exit from invocations of multiple commands after
+# the first failure.
+.SHELLFLAGS := -c -e
+
 # ━ § BEGIN SHARED MAKE·FILE CONSTRUCTS ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
 # ─ ¶ Non‐Recipe Variable Definitions ─────────────────────────────────
@@ -291,7 +297,7 @@ override xpath = $(XMLLINT) --xpath $(call quote,$1) $(call quote,$2) > /dev/nul
 override extracttext = $(PRINTF) '%s' '<transform xmlns="http://www.w3.org/1999/XSL/Transform" version="1.0"><output method="text" encoding="UTF-8"/></transform>' | $(XSLTPROC) --nonet --novalid - $(call quote,$1)
 
 # (callable) Process the provided transformation result and output the result to the provided location, given the provided relative path.
-override processresultto = if $(call xpath,/*[local-name()="raw-text" and namespace-uri()="urn:fdc:ladys.computer:20231231:Shu1She4"],$1); then $(call extracttext,$1) > $(call quote,$2); elif $(call xpath,/*[local-name()="base64-binary" and namespace-uri()="urn:fdc:ladys.computer:20231231:Shu1She4"],$1); then { $(PRINTF) '%s\n' 'begin-base64 644 -'; $(call extracttext,$1) | $(TR) -d '\t\n\f\r '; $(PRINTF) '\n%s\n' '===='; } | $(UUDECODE) -o /dev/stdout > $(call quote,$2); elif $(call xpath,/*[local-name()="archive" and namespace-uri()="urn:fdc:ladys.computer:20231231:Shu1She4"],$1); then $(MAKE) -f $(call quote,$(abspath $(THISDIR)/GNUmakefile)) $(call quote,$2) NAME=$(call quote,$3) SRC=$(call quote,$1) BUILDDIR=$(call quote,$(BUILDDIR)/archive/$3) DESTDIR=$(call quote,$(patsubst %/,%,$(dir $2))) MODE='urn:fdc:ladys.computer:20231231:Shu1She4:mode:archive'; else $(XMLLINT) --nsclean $(call quote,$1) > $(call quote,$2); fi
+override processresultto = if $(call xpath,/*[local-name()="raw-text" and namespace-uri()="urn:fdc:ladys.computer:20231231:Shu1She4"],$1); then $(call extracttext,$1) > $(call quote,$2); elif $(call xpath,/*[local-name()="base64-binary" and namespace-uri()="urn:fdc:ladys.computer:20231231:Shu1She4"],$1); then { $(PRINTF) '%s\n' 'begin-base64 644 -'; $(call extracttext,$1) | $(TR) -d '\t\n\f\r '; $(PRINTF) '\n%s\n' '===='; } | $(UUDECODE) -o /dev/stdout > $(call quote,$2); elif $(call xpath,/*[local-name()="archive" and namespace-uri()="urn:fdc:ladys.computer:20231231:Shu1She4"],$1); then $(MAKE) -f $(call quote,$(abspath $(THISDIR)/GNUmakefile)) NAME=$(call quote,$3) SRC=$(call quote,$1) BUILDDIR=$(call quote,$(BUILDDIR)/archive/$3) DESTDIR=$(call quote,$(patsubst %/,%,$(dir $2))) MODE='urn:fdc:ladys.computer:20231231:Shu1She4:mode:archive' $(call quote,$2); else $(XMLLINT) --nsclean $(call quote,$1) > $(call quote,$2); fi
 
 # ━ § BEGIN DEFAULT MAKE·FILE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
@@ -306,7 +312,7 @@ ifeq ($(MODE),urn:fdc:ladys.computer:20231231:Shu1She4:mode:default)
 # Calling this variable is useful when a given target should be updated whenever its list of prerequisites changes in addition to whenever there is a change to one of its prerequisites.
 #
 # ☡ This variable creates at least one subshell every time it is computed.
-override diffprereqs = $(if $(subst $(shell $(CAT) $(call quote,$(BUILDDIR)/lastprereqs/$1) 2> /dev/null || true),,$2),$2 FORCE$(and $(shell $(call ensuredirectory,$(BUILDDIR)/lastprereqs) && $(PRINTF) '%s\n' $(call quote,$2) > $(BUILDDIR)/lastprereqs/$1),),$2)
+override diffprereqs = $(if $(subst $(shell $(CAT) $(call quote,$(BUILDDIR)/lastprereqs/$1) 2> /dev/null || :),,$2),$2 FORCE$(and $(shell $(call ensuredirectory,$(BUILDDIR)/lastprereqs) && $(PRINTF) '%s\n' $(call quote,$2) > $(BUILDDIR)/lastprereqs/$1),),$2)
 
 # (callable) Escape special characters for use in sed regular expressions.
 override sedesc = $(subst /,[/],$(subst $$,\$$,$(subst *,\*,$(subst .,\.,$(subst [,\[,$(subst ^,\^,$(subst \,\\,$1)))))))
@@ -519,7 +525,7 @@ uninstall :
 
 # Raise an error when attempting to build any files with recursive dependencies.
 $(call built,$(recursivefiles)) :
-       @$(PRINTF) '%b\n' $(call quote,\0033[93;41mError:\0033[39;49m `$(call unbuilt,$@)´ has recursive dependencies:\n$(subst |, ,$(subst $(space),$(newline),$(foreach recursive,$(call recursives,$(call unbuilt,$@)),•|$(recursive))))) >&2 && false
+       @$(PRINTF) '%b\n' $(call quote,\0033[93;41mError:\0033[39;49m `$(call unbuilt,$@)´ has recursive dependencies:\n$(subst |, ,$(subst $(space),$(newline),$(foreach recursive,$(call recursives,$(call unbuilt,$@)),•|$(recursive))))) >&2 && exit 1
 
 # Add as a prerequisite to treat the target as tho it were phony.
 FORCE : ;