Makefile, cmd.mk, *.mk: Allow using different names for basic commands

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>

8 files changed, 68 insertions, 28 deletions

diff --git a/Makefile b/Makefile
index 7ca520426..29276f56f 100644
--- a/Makefile
+++ b/Makefile
@@ -37,12 +37,19 @@ MAKEFLAGS += --warn-undefined-variables
 
 srcdir := .
 
+
+include $(srcdir)/lib/cmd.mk
+
+
 MANDIR := $(srcdir)
 MANEXT := \.[0-9]\w*
 
 
-MANPAGES := $(sort $(shell find $(MANDIR)/man*/ -type f | grep '$(MANEXT)'))
-MANDIRS  := $(sort $(shell find $(MANDIR)/man* -type d))
+MANPAGES := $(shell $(FIND) $(MANDIR)/man*/ -type f \
+		| $(GREP) '$(MANEXT)' \
+		| $(SORT))
+MANDIRS  := $(shell $(FIND) $(MANDIR)/man* -type d \
+		| $(SORT))
 
 
 .PHONY: all
diff --git a/lib/build-html.mk b/lib/build-html.mk
index 7caa8f755..fad72eb64 100644
--- a/lib/build-html.mk
+++ b/lib/build-html.mk
@@ -9,6 +9,7 @@ MAKEFILE_BUILD_HTML_INCLUDED := 1
 
 
 include $(srcdir)/lib/build.mk
+include $(srcdir)/lib/cmd.mk
 
 
 htmlext  := .html
@@ -30,7 +31,8 @@ _HTMLDIRS  := $(patsubst $(MANDIR)/%,$(_HTMLDIR)/%/.,$(MANDIRS))
 # The sed removes the lines "Content-type: text/html\n\n"
 $(_HTMLPAGES): $(_HTMLDIR)/%.html: $(MANDIR)/% | $$(@D)/.
 	$(info MAN2HTML	$@)
-	$(MAN2HTML) $(MAN2HTMLFLAGS) $< | sed -e 1,2d >$@
+	$(MAN2HTML) $(MAN2HTMLFLAGS) $< \
+	| $(SED) -e 1,2d >$@
 
 $(_HTMLDIRS): %/.: | $$(dir %). $(_HTMLDIR)/.
 
diff --git a/lib/build-src.mk b/lib/build-src.mk
index 57c4731ae..b47a5a756 100644
--- a/lib/build-src.mk
+++ b/lib/build-src.mk
@@ -9,6 +9,7 @@ MAKEFILE_BUILD_SRC_INCLUDED := 1
 
 
 include $(srcdir)/lib/build.mk
+include $(srcdir)/lib/cmd.mk
 include $(srcdir)/lib/lint.mk
 
 
@@ -47,14 +48,15 @@ MAN := man
 
 _SRCPAGEDIRS   := $(patsubst $(MANDIR)/%,$(_SRCDIR)/%.d,$(LINTMAN))
 
-_UNITS_src_src := $(sort $(patsubst $(MANDIR)/%,$(_SRCDIR)/%,$(shell \
-		find $(MANDIR)/man*/ -type f \
-		| grep '$(MANEXT)$$' \
-		| xargs grep -l '^\.TH ' \
+_UNITS_src_src := $(patsubst $(MANDIR)/%,$(_SRCDIR)/%,$(shell \
+		$(FIND) $(MANDIR)/man*/ -type f \
+		| $(GREP) '$(MANEXT)$$' \
+		| $(XARGS) $(GREP) -l '^\.TH ' \
 		| while read m; do \
-			<$$m \
-			sed -n "s,^\... SRC BEGIN (\(.*.[ch]\))$$,$$m.d/\1,p"; \
-		done)))
+		    <$$m \
+		    $(SED) -n "s,^\... SRC BEGIN (\(.*.[ch]\))$$,$$m.d/\1,p"; \
+		done \
+		| $(SORT)))
 _UNITS_src_h   := $(filter %.h,$(_UNITS_src_src))
 _UNITS_src_c   := $(filter %.c,$(_UNITS_src_src))
 _UNITS_src_o   := $(patsubst %.c,%.o,$(_UNITS_src_c))
@@ -71,13 +73,13 @@ $(_UNITS_src_c):   $$(filter $$(@D)/%.h,$(_UNITS_src_h))
 $(_UNITS_src_src):
 	$(info SED	$@)
 	<$< \
-	sed -n \
+	$(SED) -n \
 		-e '/^\.TH/,/^\.SH/{/^\.SH/!p}' \
 		-e '/^\.SH EXAMPLES/p' \
 		-e "/^\... SRC BEGIN ($(@F))$$/,/^\... SRC END$$/p" \
 	| $(MAN) -P cat -l - \
-	| sed '/^[^ ]/d' \
-	| sed 's/^       //' \
+	| $(SED) '/^[^ ]/d' \
+	| $(SED) 's/^       //' \
 	>$@
 
 $(_UNITS_src_o): $(_SRCDIR)/%.o: $(_SRCDIR)/%.c
diff --git a/lib/cmd.mk b/lib/cmd.mk
new file mode 100644
index 000000000..662209966
--- /dev/null
+++ b/lib/cmd.mk
@@ -0,0 +1,23 @@
+########################################################################
+# Copyright (C) 2022  Alejandro Colomar <alx.manpages@gmail.com>
+# SPDX-License-Identifier:  GPL-2.0  OR  LGPL-2.0
+########################################################################
+
+
+ifndef MAKEFILE_CMD_INCLUDED
+MAKEFILE_CMD_INCLUDED := 1
+
+
+FIND  := find
+GIT   := git
+GREP  := grep
+GZIP  := gzip
+SED   := sed
+SORT  := sort
+TAC   := tac
+TAR   := tar
+XARGS := xargs
+XZ    := xz
+
+
+endif  # MAKEFILE_CMD_INCLUDED
diff --git a/lib/dist.mk b/lib/dist.mk
index 570c81f2c..663347cb0 100644
--- a/lib/dist.mk
+++ b/lib/dist.mk
@@ -9,28 +9,29 @@ MAKEFILE_DIST_INCLUDED := 1
 
 
 include $(srcdir)/lib/build.mk
+include $(srcdir)/lib/cmd.mk
 
 
-DISTNAME    := $(shell git describe 2>/dev/null)
+DISTNAME    := $(shell $(GIT) describe 2>/dev/null)
 DISTFILE    := $(builddir)/$(DISTNAME).tar
 compression := gz xz
 dist        := $(foreach x,$(compression),dist-$(x))
 
 
-$(DISTFILE): $(shell git ls-files 2>/dev/null) | $$(@D)/.
+$(DISTFILE): $(shell $(GIT) ls-files 2>/dev/null) | $$(@D)/.
 	$(info TAR	$@)
-	tar cf $@ -T /dev/null
-	git ls-files \
-	| sed 's,^,./,' \
-	| xargs tar rf $@ -C $(srcdir) --transform 's,^\.,$(DISTNAME),'
+	$(TAR) cf $@ -T /dev/null
+	$(GIT) ls-files \
+	| $(SED) 's,^,./,' \
+	| $(XARGS) $(TAR) rf $@ -C $(srcdir) --transform 's,^\.,$(DISTNAME),'
 
 $(DISTFILE).gz: %.gz: % | $$(@D)/.
 	$(info GZIP	$@)
-	gzip -knf $<
+	$(GZIP) -knf $<
 
 $(DISTFILE).xz: %.xz: % | $$(@D)/.
 	$(info XZ	$@)
-	xz -kf $<
+	$(XZ) -kf $<
 
 
 .PHONY: dist-tar
diff --git a/lib/lint-c.mk b/lib/lint-c.mk
index 88941f114..9d27da786 100644
--- a/lib/lint-c.mk
+++ b/lib/lint-c.mk
@@ -9,6 +9,7 @@ MAKEFILE_LINT_C_INCLUDED := 1
 
 
 include $(srcdir)/lib/build-src.mk
+include $(srcdir)/lib/cmd.mk
 include $(srcdir)/lib/lint.mk
 
 
@@ -55,7 +56,7 @@ $(_LINT_c_checkpatch): %.lint-c.checkpatch.touch: %.c
 $(_LINT_c_clang-tidy): %.lint-c.clang-tidy.touch: %.c
 	$(info LINT (clang-tidy)	$@)
 	$(CLANG-TIDY) $(CLANG-TIDYFLAGS) $< -- $(CPPFLAGS) $(CFLAGS) 2>&1 \
-	| sed '/generated\.$$/d'
+	| $(SED) '/generated\.$$/d'
 	touch $@
 
 $(_LINT_c_cpplint): %.lint-c.cpplint.touch: %.c
@@ -66,9 +67,9 @@ $(_LINT_c_cpplint): %.lint-c.cpplint.touch: %.c
 $(_LINT_c_iwyu): %.lint-c.iwyu.touch: %.c
 	$(info LINT (iwyu)	$@)
 	$(IWYU) $(IWYUFLAGS) $(CPPFLAGS) $(CFLAGS) $< 2>&1 \
-	| tac \
-	| sed '/correct/{N;d}' \
-	| tac
+	| $(TAC) \
+	| $(SED) '/correct/{N;d}' \
+	| $(TAC)
 	touch $@
 
 
diff --git a/lib/lint-man.mk b/lib/lint-man.mk
index 76839db23..082c4fe44 100644
--- a/lib/lint-man.mk
+++ b/lib/lint-man.mk
@@ -8,13 +8,14 @@ ifndef MAKEFILE_LINT_MAN_INCLUDED
 MAKEFILE_LINT_MAN_INCLUDED := 1
 
 
+include $(srcdir)/lib/cmd.mk
 include $(srcdir)/lib/lint.mk
 
 
 TMACDIR := $(SYSCONFDIR)/groff/tmac
 
 
-TMACFILES            := $(sort $(shell find $(TMACDIR) -not -type d))
+TMACFILES            := $(shell $(FIND) $(TMACDIR) -not -type d | $(SORT))
 TMACNAMES            := $(basename $(notdir $(TMACFILES)))
 GROFF_CHECKSTYLE_LVL := 3
 DEFAULT_GROFFFLAGS   := -man
diff --git a/lib/lint.mk b/lib/lint.mk
index b4fff3631..55fa5e1f5 100644
--- a/lib/lint.mk
+++ b/lib/lint.mk
@@ -9,6 +9,7 @@ MAKEFILE_LINT_INCLUDED := 1
 
 
 include $(srcdir)/lib/build.mk
+include $(srcdir)/lib/cmd.mk
 
 
 SYSCONFDIR := $(srcdir)/etc
@@ -16,8 +17,10 @@ SYSCONFDIR := $(srcdir)/etc
 _LINTDIR   := $(builddir)/lint
 
 
-LINTMAN   := $(shell find $(MANDIR)/man*/ -type f | grep '$(MANEXT)' \
-                     | xargs grep -l '^\.TH ' | sort))
+LINTMAN   := $(shell $(FIND) $(MANDIR)/man*/ -type f \
+		| $(GREP) '$(MANEXT)' \
+		| $(XARGS) $(GREP) -l '^\.TH ' \
+		| $(SORT))
 _LINTDIRS := $(patsubst $(MANDIR)/%,$(_LINTDIR)/%/.,$(MANDIRS))