diff --git a/qpms/error.c b/qpms/error.c
new file mode 100644
index 0000000..6027190
--- /dev/null
+++ b/qpms/error.c
@@ -0,0 +1,48 @@
+#include "qpms_error.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+
+void qpms_pr_error(const char *fmt, ...) {
+  fflush(stdout);
+  va_list ap;
+  va_start(ap, fmt);
+  vfprintf(stderr, fmt, ap);
+  va_end(ap);
+  fputc('\n', stderr);
+  fflush(stderr);
+  abort();
+}
+
+
+//void qpms_error(const char *fmt, ...);
+
+void qpms_pr_error_at_line(const char *filename, unsigned int linenum,
+		const char *fmt, ...) {
+  fflush(stdout);
+  fprintf(stderr, "%s:%u: ", filename, linenum);
+  va_list ap;
+  va_start(ap, fmt);
+  vfprintf(stderr, fmt, ap);
+  va_end(ap);
+  fputc('\n', stderr);
+  fflush(stderr);
+  abort();
+}
+
+void qpms_pr_error_at_flf(const char *filename, unsigned int linenum,
+    const char *func,
+		const char *fmt, ...) {
+  fflush(stdout);
+  fprintf(stderr, "%s:%u, %s: ", filename, linenum, func);
+  va_list ap;
+  va_start(ap, fmt);
+  vfprintf(stderr, fmt, ap);
+  va_end(ap);
+  fputc('\n', stderr);
+  fflush(stderr);
+  abort();
+}
+//void qpms_error_at_line(const char *filename, unsigned int linenum,
+//		const char *fmt, ...);
+
diff --git a/qpms/qpms_error.h b/qpms/qpms_error.h
new file mode 100644
index 0000000..45f88aa
--- /dev/null
+++ b/qpms/qpms_error.h
@@ -0,0 +1,19 @@
+#ifndef QPMS_ERROR_H
+#define QPMS_ERROR_H
+
+/// Provisional error message with abort();
+void qpms_pr_error(const char *fmt, ...);
+//void qpms_error(const char *fmt, ...);
+
+/// Provisional error message with abort(), indicating source and line number.
+void qpms_pr_error_at_line(const char *filename, unsigned int linenum,
+		const char *fmt, ...);
+
+void qpms_pr_error_at_flf(const char *filename, unsigned int linenum,
+		const char *func,
+	       const char *fmt, ...);
+
+//void qpms_error_at_line(const char *filename, unsigned int linenum,
+//		const char *fmt, ...);
+
+#endif