fileis(1): scrap libfileis(3), work on rewriting scrut(1) in Rust

Makefile

@@ -32,7 +32,7 @@ RUSTLIBS = --extern getopt=build/o/libgetopt.rlib \
 CFLAGS += -I$(SYSEXITS) -Iinclude
 
 .PHONY: all
-all: dj false fop hru intcmp mm npc rpn scrut str strcmp swab true
+all: dj false fileis fop hru intcmp mm npc rpn scrut str strcmp swab true
 
 # keep build/include until bindgen(1) has stdin support
 # https://github.com/rust-lang/rust-bindgen/issues/2703
@@ -87,11 +87,6 @@ build/o/libsysexits.rlib: build/include/sysexits.h
 build/include/sysexits.h: build $(SYSEXITS)sysexits.h
 	printf '\043define EXIT_FAILURE 1\n' | cat - $(SYSEXITS)sysexits.h > $@
 
-.PHONY: libfileis
-libfileis: build/o/libfileis.o
-build/o/libfileis.o: build src/libfileis.c
-	$(CC) $(CFLAGS) -c -o $@ src/libfileis.c
-
 .PHONY: dj
 dj: build/bin/dj
 build/bin/dj: src/dj.c build
@@ -102,6 +97,11 @@ false: build/bin/false
 build/bin/false: src/false.c build
 	$(CC) $(CFLAGS) -o $@ src/false.c
 
+.PHONY: fileis
+fileis: build/bin/fileis
+build/bin/fileis: src/fileis.rs build
+	$(RUSTC) $(RUSTFLAGS) $(RUSTLIBS) -o $@ src/fileis.rs
+
 .PHONY: fop
 fop: build/bin/fop
 build/bin/fop: src/fop.rs build rustlibs
@@ -132,11 +132,6 @@ rpn: build/bin/rpn
 build/bin/rpn: src/rpn.rs build rustlibs
 	$(RUSTC) $(RUSTFLAGS) $(RUSTLIBS) -o $@ src/rpn.rs
 
-.PHONY: scrut
-scrut: build/bin/scrut
-build/bin/scrut: src/scrut.c build libfileis
-	$(CC) $(CFLAGS) -o $@ src/scrut.c build/o/libfileis.o
-
 .PHONY: str
 str: build/bin/str
 build/bin/str: src/str.c build