Stop using 'which' command in build scripts

These days, it becomes normal where "which" command is not found
in minimal container images such as fedora and archlinux.

Since POSIX 2008, a portable and efficient way of testing command
availability is:

    command -v <command_name>

Use it in build scripts (via make and shell variable WHICH) instead.

Link: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/command.html
Signed-off-by: Akira Yokosawa <[email protected]>

Makefile

@@ -1,5 +1,6 @@
 SHELL = /bin/bash
 LATEX ?= pdflatex
+WHICH = command -v
 
 GITREFSTAGS := $(shell ls -d .git/refs/tags 2>/dev/null)
 
@@ -101,16 +102,16 @@ PDFTARGETS_OF_EPSOTHER := $(filter-out $(PDFTARGETS_OF_EPSORIG) $(PDFTARGETS_OF_
 BIBSOURCES := bib/*.bib alphapf.bst
 
 # required commands
-LATEX_CMD := $(shell which $(LATEX) 2>/dev/null)
-DOT := $(shell which dot 2>/dev/null)
-FIG2EPS := $(shell which fig2eps 2>/dev/null)
-FIG2DEV := $(shell which fig2dev 2>/dev/null)
-INKSCAPE := $(shell which inkscape 2>/dev/null)
+LATEX_CMD := $(shell $(WHICH) $(LATEX) 2>/dev/null)
+DOT := $(shell $(WHICH) dot 2>/dev/null)
+FIG2EPS := $(shell $(WHICH) fig2eps 2>/dev/null)
+FIG2DEV := $(shell $(WHICH) fig2dev 2>/dev/null)
+INKSCAPE := $(shell $(WHICH) inkscape 2>/dev/null)
 ifdef INKSCAPE
   INKSCAPE_ONE := $(shell inkscape --version 2>/dev/null | grep -c "Inkscape 1")
 endif
-LATEXPAND := $(shell which latexpand 2>/dev/null)
-QPDF := $(shell which qpdf 2>/dev/null)
+LATEXPAND := $(shell $(WHICH) latexpand 2>/dev/null)
+QPDF := $(shell $(WHICH) qpdf 2>/dev/null)
 
 # required fonts
 STEELFONT := $(shell fc-list | grep -c -i steel)

a2ping-rule.mk

@@ -4,7 +4,7 @@
 #
 # Authors: Akira Yokosawa <[email protected]>
 
-A2PING := $(shell which a2ping 2>/dev/null)
+A2PING := $(shell $(WHICH) a2ping 2>/dev/null)
 
 ifdef A2PING
   GS_950_OR_LATER := $(shell gs --version | grep -c -E "^(9\.[5-9]|10\.[0-9]).?")

epstopdf-rule.mk

@@ -4,7 +4,7 @@
 #
 # Authors: Akira Yokosawa <[email protected]>
 
-EPSTOPDF := $(shell which epstopdf 2>/dev/null)
+EPSTOPDF := $(shell $(WHICH) epstopdf 2>/dev/null)
 GS_953_OR_LATER := $(shell gs --version | grep -c -E "^(9\.5[3-9]|10\.[0-9]).?")
 GS_OPT=--gsopt=-dPDFSETTINGS=/ebook
 

utilities/cleverefcheck.sh

@@ -1,6 +1,7 @@
 #!/bin/sh
 
 : ${GREP:=grep}
+: ${WHICH:=command -v}
 CREFPTN='\\[Cc](ln)?ref[{][^}]+}\s*[{][^}]+}'
 
 tex_sources_all=`find . -name "*.tex" -print`
@@ -41,6 +42,6 @@ do
 	fi
 done
 if [ $grep_z_opt -eq 0 ] ; then
-	echo "`which $GREP` doesn't know the -z option."
+	echo "`$WHICH $GREP` doesn't know the -z option."
 	echo "Skipping \\crefrange checks."
 fi

utilities/mpostcheck.sh

@@ -111,6 +111,8 @@
 #   follow the instruction given there.
 #-------------------------------------------------------------------
 
+: ${WHICH:=command -v}
+
 dogrep() {
 	texsrc=`find . -name "*.tex" -print`
 	bibsrc=`find . -name "*.bib" -print`
@@ -130,7 +132,7 @@ dogrep() {
 	fi
 }
 
-if which kpsewhich >/dev/null
+if $WHICH kpsewhich >/dev/null
 then
 	command_list_orig=`kpsewhich -var-value=shell_escape_commands`
 	command_list=`echo $command_list_orig | sed -E "s/r-u?p?mpost,//g"`

utilities/precheck.sh

@@ -11,6 +11,7 @@ LC_TIME=C
 : ${SED:=sed}
 : ${DATE:=date}
 : ${VERBOSE:=}
+: ${WHICH:=command -v}
 
 fatal=""
 
@@ -68,7 +69,7 @@ if [ "$sed_result" != "OK" -o "$VERBOSE" != "" ] ; then
 	if [ "$sed_result" = "OK" ] ; then
 		echo "OK."
 	else
-		echo "$SED (at `which $SED`) failed the test!"
+		echo "$SED (at `$WHICH $SED`) failed the test!"
 	fi
 fi
 if [ "$date_result" != "OK" -o "$VERBOSE" != "" ] ; then
@@ -79,7 +80,7 @@ if [ "$date_result" != "OK" -o "$VERBOSE" != "" ] ; then
 	echo -n "$date_flavor ... "
 	if [ "$date_flavor" = "Unknown" ] ; then
 		echo
-		echo "Unknown date command found at `which $DATE`."
+		echo "Unknown date command found at `$WHICH $DATE`."
 	else
 		if [ "$month" = "January" ] ; then
 			echo "OK."