diff --git a/c/input/line_readers.c b/c/input/line_readers.c
index 2215d8b20..4a37ef6de 100644
--- a/c/input/line_readers.c
+++ b/c/input/line_readers.c
@@ -148,3 +148,46 @@ ssize_t local_getdelim(char** restrict pline, size_t* restrict plinecap, int del
 //
 // reuse linecap on subsequent calls. power of two above last readlen.
 // work autodetect deeper into the callstack
+
+// ----------------------------------------------------------------
+char* mlr_alloc_read_line_single_delimiter(
+	FILE*   fp,
+	int     delimiter,
+	int*    preached_eof,
+	size_t* pold_then_new_strlen,
+	size_t* pold_then_new_linecap)
+{
+	// xxx wip
+	size_t linecap = power_of_two_above(*pold_then_new_strlen);
+	char* restrict line = mlr_malloc_or_die(linecap);
+	char* restrict p = line;
+	int reached_eof = FALSE;
+	int c;
+
+	while (TRUE) {
+		size_t offset = p - line;
+		if (offset >= linecap) {
+			linecap = linecap << 1;
+			line = mlr_realloc_or_die(line, linecap);
+			p = line + offset;
+		}
+		c = mlr_arch_getc(fp);
+		if (c == delimiter) {
+			*(p++) = 0;
+			break;
+		} else if (c == EOF) {
+			*(p++) = 0;
+			if (p == line)
+				reached_eof = TRUE;
+			break;
+		} else {
+			*(p++) = c;
+		}
+	}
+
+	*preached_eof = reached_eof;
+	*pold_then_new_strlen = p - line - 1; // exclude null terminator
+	*pold_then_new_linecap = linecap;
+
+	return line;
+}
diff --git a/c/input/line_readers.h b/c/input/line_readers.h
index 12e61b4e0..79b6eabac 100644
--- a/c/input/line_readers.h
+++ b/c/input/line_readers.h
@@ -24,4 +24,25 @@ char*  mlr_get_sline(FILE* input_stream, char* irs, int irslen);
 // inside mlr_arch.c, for unit-testing visibility.
 ssize_t local_getdelim(char** restrict pline, size_t* restrict plinecap, int delimiter, FILE* restrict stream);
 
+// xxx type up comments:
+// * in delimiter (single/multiple)
+// * in fp
+// * -in do_auto_line_term- separate variant
+// * -inout pctx- separate variant
+// * out line
+// * out reached eof
+// * inout strlen (old/new). DEFAULT_SIZE @ first call
+// * inout linecap (old/new) DEFAULT_SIZE @ first call
+//
+// reuse linecap on subsequent calls. power of two above last readlen.
+// work autodetect deeper into the callstack
+
+#define MLR_ALLOC_READ_LINE_INITIAL_SIZE 128
+char* mlr_alloc_read_line_single_delimiter(
+	FILE*   fp,
+	int     delimiter,
+	int*    preached_eof,
+	size_t* pold_then_new_strlen,
+	size_t* pold_then_new_linecap);
+
 #endif // LINE_READERS_H
diff --git a/c/unit_test/test_line_readers.c b/c/unit_test/test_line_readers.c
index 824d20981..e291cbc31 100644
--- a/c/unit_test/test_line_readers.c
+++ b/c/unit_test/test_line_readers.c
@@ -26,6 +26,7 @@ static FILE* fopen_or_die(char* filename) {
 	return fp;
 }
 
+// ----------------------------------------------------------------
 static char* test_getdelim_impl(getdelim_t* pgetdelim) {
 	char delimiter = '\n';
 	char* contents = NULL;
@@ -108,6 +109,92 @@ static char* test_getdelim_impl(getdelim_t* pgetdelim) {
 	return NULL;
 }
 
+// ----------------------------------------------------------------
+static char* test_mlr_alloc_read_line_single_delimiter() {
+#if 0
+	char   delimiter = '\n';
+	char*  path = NULL;
+	FILE*  fp = NULL;
+	char*  contents = NULL;
+	char*  line = NULL;
+	int    reached_eof = FALSE;
+	size_t linelen = 0;
+	size_t linecap = 0;
+
+	//  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+	contents = "";
+	path = write_temp_file_or_die(contents);
+	fp = fopen_or_die(path);
+
+	// Read line
+	linecap = 4;
+	line = mlr_alloc_read_line_single_delimiter(fp, delimiter, &reached_eof, &linelen, &linecap);
+	printf("reof=%d,linelen=%d,linecap=%d,line=\"%s\"\n", (int)reached_eof, (int)linelen, (int)linecap, line);
+	mu_assert_lf(line != NULL);
+	mu_assert_lf(streq(line, ""));
+	mu_assert_lf(reached_eof == TRUE);
+	mu_assert_lf(linelen == strlen(""));
+	mu_assert_lf(linecap > linelen);
+
+	// Read past EOF
+	line = mlr_alloc_read_line_single_delimiter(fp, delimiter, &reached_eof, &linelen, &linecap);
+	mu_assert_lf(line != NULL);
+	mu_assert_lf(streq(line, ""));
+	mu_assert_lf(reached_eof == TRUE);
+
+	fclose(fp);
+	unlink_file_or_die(path);
+
+
+	//  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+	contents = "\n";
+	path = write_temp_file_or_die(contents);
+	fp = fopen_or_die(path);
+
+	// Read line
+	line = NULL;
+	linecap = 0;
+	rc = (*pgetdelim)(&line, &linecap, delimiter, fp);
+	mu_assert_lf(rc == 1);
+	mu_assert_lf(streq(line, "\n"));
+	mu_assert_lf(linecap >= 1+strlen(contents));
+
+	// Read past EOF
+	line = NULL;
+	linecap = 0;
+	rc = (*pgetdelim)(&line, &linecap, delimiter, fp);
+	mu_assert_lf(rc == -1);
+
+
+	fclose(fp);
+	unlink_file_or_die(path);
+
+	//  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+	contents = "\r\n";
+	path = write_temp_file_or_die(contents);
+	fp = fopen_or_die(path);
+
+	// Read line
+	line = NULL;
+	linecap = 0;
+	rc = (*pgetdelim)(&line, &linecap, delimiter, fp);
+	mu_assert_lf(rc == 2);
+	mu_assert_lf(streq(line, "\r\n"));
+	mu_assert_lf(linecap >= 1+strlen(contents));
+
+	// Read past EOF
+	line = NULL;
+	linecap = 0;
+	rc = (*pgetdelim)(&line, &linecap, delimiter, fp);
+	mu_assert_lf(rc == -1);
+
+
+	fclose(fp);
+	unlink_file_or_die(path);
+#endif
+	return NULL;
+}
+
 // ----------------------------------------------------------------
 // On unixish platforms this is testing the system getdelim() which is correct by definition.
 // (At least, we verify it's behaving as we expect.) On Windows, this tests our local_getdelim
@@ -126,7 +213,7 @@ static char* test_getdelim() {
 // ================================================================
 static char * run_all_tests() {
 	mu_run_test(test_getdelim);
-	// xxx WIP mu_run_test(test_local_getdelim);
+	mu_run_test(test_mlr_alloc_read_line_single_delimiter);
 	return 0;
 }