--- a/scripts/awk	Thu May 23 23:35:52 2019 +0200
+++ b/scripts/awk	Sat May 25 11:36:31 2019 +0200
@@ -47,9 +47,17 @@
 	done | relpipe-in-cli generate-from-stdin args 2 i integer value string | relpipe-out-tabular
 }
 
+realAWK() {
+	/usr/bin/awk "$@"
+	echo "$?" > "$logDir/awk-status.log"
+}
+
 formatArgsTxt "$@" > "$logDir/awk-args.log";
 
-tee "$logDir/awk-stdin.log" | /usr/bin/awk "$@" 2> "$logDir/awk-stderr.log" | tee "$logDir/awk-stdout.log";
+tee "$logDir/awk-stdin.log" | realAWK "$@" 2> "$logDir/awk-stderr.log" | tee "$logDir/awk-stdout.log";
+
+cat "$logDir/awk-stderr.log" >&2;
+exit `cat "$logDir/awk-status.log"`;
 
 # Use e.g. GNU Screen with four windows to watch files:
 # watchFile() { while inotifywait "$1" &>/dev/null ; do clear; cat "$1" ; done; }

--- a/src/AwkHandler.h	Thu May 23 23:35:52 2019 +0200
+++ b/src/AwkHandler.h	Sat May 25 11:36:31 2019 +0200
@@ -133,9 +133,11 @@
 	void cleanUp() {
 		if (awkInputWriterFD >= 0) {
 			closeOrThrow(awkInputWriterFD);
-			// FIXME: check exit codes
-			__pid_t waitResult1 = wait(NULL);
-			__pid_t waitResult2 = wait(NULL);
+			int error1;
+			int error2;
+			__pid_t waitPID1 = wait(&error1);
+			__pid_t waitPID2 = wait(&error2);
+			if (error1 || error2) throw cli::RelpipeCLIException(L"The child process returned an error exit code.", cli::CLI::EXIT_CODE_UNEXPECTED_ERROR); // TODO: better exceptions?
 			awkInputWriterFD = -1;
 		}