A C implementation of "not" that handles fatal signals rather more

intelligently than the shell implementation. C code by Jaroslav Stava.

I have done a rudimentary review and checked that tests still pass.

test/Makefile.in

@@ -25,9 +25,12 @@ abs_builddir = @abs_builddir@
 abs_top_builddir = @abs_top_builddir@
 abs_top_srcdir = @abs_top_srcdir@
 
-all: init.sh
+all: bin/not init.sh
 	sh harness.sh
 
+bin/not: .bin-dir-stamp
+	$(CC) -o bin/not not.c
+
 init.sh: Makefile.in .bin-dir-stamp
 	rm -f $@-t $@
 	echo 'top_srcdir=$(top_srcdir)' >> $@-t
@@ -49,7 +52,7 @@ T = $(wildcard t-*.sh)
 Makefile: $(srcdir)/Makefile.in $(top_builddir)/config.status
 	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@
 
-$(T): init.sh
+$(T): bin/not init.sh
 	sh harness.sh $@
 
 .bin-dir-stamp: lvm-wrapper

test/not.c

@@ -0,0 +1,36 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+int main(int args, char **argv) {
+	pid_t pid;
+	int status;
+	int FAILURE = 6;
+
+	if (args < 2) {
+		fprintf(stderr, "Need args\n");
+		return FAILURE;
+	}
+
+	pid = fork();
+	if (pid == -1) {
+		fprintf(stderr, "Could not fork\n");
+		return FAILURE;
+	} else if (pid == 0) { 	/* child */
+		execvp(argv[1], &argv[1]);
+		/* should not be accessible */
+		return FAILURE;
+	} else {		/* parent */
+		waitpid(pid, &status, 0);
+		if (!WIFEXITED(status)) {
+			/* did not exit correctly */
+			return FAILURE;
+		}
+		/* return the opposite */
+		return !WEXITSTATUS(status);
+	}
+	/* not accessible */
+	return FAILURE;
+}

test/test-utils.sh

@@ -17,16 +17,6 @@ aux() {
 	#"$@"
 }
 
-not () {
-	"$@" && exit 1 || {
-		err="$?"
-		if test "$err" = 129; then
-			echo "fatal error $err"
-			exit 1
-		fi
-	}
-}
-
 STACKTRACE() {
 	trap - ERR;
 	i=0;