diff --git a/c/experimental/getlines.c b/c/experimental/getlines.c
index e3926e89b..093f92815 100644
--- a/c/experimental/getlines.c
+++ b/c/experimental/getlines.c
@@ -28,76 +28,71 @@ static FILE* fopen_or_die(char* filename) {
 	return fp;
 }
 
-//// ================================================================
-//static int read_file_mlr_get_line(char* filename, int do_write) {
-//	FILE* fp = fopen_or_die(filename);
-//	int bc = 0;
-//	while (1) {
-//		char* line = mlr_get_cline(fp, '\n');
-//		if (line == NULL)
-//			break;
-//		bc += strlen(line);
-//		if (do_write) {
-//			fputs(line, stdout);
-//			fputc('\n', stdout);
-//		}
-//		free(line);
-//	}
-//	fclose(fp);
-//	return bc;
-//}
+// ================================================================
+static int read_file_mlr_alloc_read_line_single_delimiter_no_autodetect(char* filename, int do_write) {
+	FILE* fp = fopen_or_die(filename);
+	int bc = 0;
+	size_t line_length = MLR_ALLOC_READ_LINE_INITIAL_SIZE;
+	while (1) {
+		char* line = mlr_alloc_read_line_single_delimiter(
+			fp, '\n', &line_length, FALSE, NULL);
+		if (line == NULL)
+			break;
+		bc += strlen(line);
+		if (do_write) {
+			fputs(line, stdout);
+			fputc('\n', stdout);
+		}
+		free(line);
+	}
+	fclose(fp);
+	return bc;
+}
 
-//// ================================================================
-//static int read_file_mlr_getsdelim(char* filename, int do_write) {
-//	FILE* fp = fopen_or_die(filename);
-//	char* irs = "\r\n";
-//	int irslen = strlen(irs);
-//	int bc = 0;
-//	while (1) {
-//		char* line = mlr_get_sline(fp, irs, irslen);
-//		if (line == NULL)
-//			break;
-//		//bc += linelen; // available by API, but make a fair comparison
-//		bc += strlen(line);
-//		if (do_write) {
-//			fputs(line, stdout);
-//			fputc('\n', stdout);
-//		}
-//		free(line);
-//	}
-//	fclose(fp);
-//	return bc;
-//}
+// ================================================================
+static int read_file_mlr_alloc_read_line_single_delimiter_with_autodetect(char* filename, int do_write) {
+	FILE* fp = fopen_or_die(filename);
+	int bc = 0;
+	size_t line_length = MLR_ALLOC_READ_LINE_INITIAL_SIZE;
+	context_t ctx;
+	context_init_from_first_file_name(&ctx, "fake-file-name");
 
-//// ================================================================
-//static int popen_file_mlr_getsdelim(char* reader, char* filename, int do_write) {
-//	char* command = mlr_malloc_or_die(strlen(reader) + 1 + strlen(filename) + 1);
-//	strcpy(command, reader);
-//	strcat(command, " ");
-//	strcat(command, filename);
-//	FILE* fp = popen(command, "r");
-//	if (fp == NULL) {
-//		perror("popen");
-//		exit(1);
-//	}
-//	char* irs = "\r\n";
-//	int irslen = strlen(irs);
-//	int bc = 0;
-//	while (1) {
-//		char* line = mlr_get_sline(fp, irs, irslen);
-//		if (line == NULL)
-//			break;
-//		//bc += linelen; // available by API, but make a fair comparison
-//		bc += strlen(line);
-//		if (do_write) {
-//			fputs(line, stdout);
-//			fputc('\n', stdout);
-//		}
-//		free(line);
-//	}
-//	pclose(fp);
-//	return bc;
-//}
+	while (1) {
+		char* line = mlr_alloc_read_line_single_delimiter(
+			fp, '\n', &line_length, TRUE, &ctx);
+		if (line == NULL)
+			break;
+		bc += strlen(line);
+		if (do_write) {
+			fputs(line, stdout);
+			fputc('\n', stdout);
+		}
+		free(line);
+	}
+	fclose(fp);
+	return bc;
+}
+
+// ================================================================
+static int read_file_mlr_alloc_read_line_multiple_delimiter(char* filename, int do_write) {
+	FILE* fp = fopen_or_die(filename);
+	int bc = 0;
+	size_t line_length = MLR_ALLOC_READ_LINE_INITIAL_SIZE;
+
+	while (1) {
+		char* line = mlr_alloc_read_line_multiple_delimiter(fp, "\n", 1, &line_length);
+		if (line == NULL)
+			break;
+		bc += strlen(line);
+		if (do_write) {
+			fputs(line, stdout);
+			fputc('\n', stdout);
+		}
+		free(line);
+	}
+	fclose(fp);
+	return bc;
+}
 
 // ================================================================
 static char* read_line_fgetc(FILE* fp, char* irs) {
@@ -387,26 +382,26 @@ int main(int argc, char** argv) {
 
 	for (int i = 0; i < nreps; i++) {
 
-//		s = get_systime();
-//		bc = read_file_mlr_get_line(filename, do_write);
-//		e = get_systime();
-//		t = e - s;
-//		printf("type=getdelim,t=%.6lf,n=%d\n", t, bc);
-//		fflush(stdout);
+		s = get_systime();
+		bc = read_file_mlr_alloc_read_line_single_delimiter_no_autodetect(filename, do_write);
+		e = get_systime();
+		t = e - s;
+		printf("type=single_delim_no_auto,t=%.6lf,n=%d\n", t, bc);
+		fflush(stdout);
 
-//		s = get_systime();
-//		bc = read_file_mlr_getsdelim(filename, do_write);
-//		e = get_systime();
-//		t = e - s;
-//		printf("type=mlr_getsdelim,t=%.6lf,n=%d\n", t, bc);
-//		fflush(stdout);
+		s = get_systime();
+		bc = read_file_mlr_alloc_read_line_single_delimiter_with_autodetect(filename, do_write);
+		e = get_systime();
+		t = e - s;
+		printf("type=single_delim_with_auto,t=%.6lf,n=%d\n", t, bc);
+		fflush(stdout);
 
-//		s = get_systime();
-//		bc = popen_file_mlr_getsdelim("zcat -cf < ", filename, do_write);
-//		e = get_systime();
-//		t = e - s;
-//		printf("type=mlr_popen_getsdelim,t=%.6lf,n=%d\n", t, bc);
-//		fflush(stdout);
+		s = get_systime();
+		bc = read_file_mlr_alloc_read_line_multiple_delimiter(filename, do_write);
+		e = get_systime();
+		t = e - s;
+		printf("type=multiple_delim,t=%.6lf,n=%d\n", t, bc);
+		fflush(stdout);
 
 		s = get_systime();
 		bc = read_file_fgetc_fixed_len(filename, do_write);
diff --git a/c/input/line_readers.h b/c/input/line_readers.h
index 1ed1e84e3..6ebf04266 100644
--- a/c/input/line_readers.h
+++ b/c/input/line_readers.h
@@ -8,19 +8,10 @@
 // * The caller should free the return value.
 // * The line-terminator is not returned as part of the string.
 // * Null is returned at EOF.
-
-// 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
+// * Simiar to getdelim but customized for Miller: in particular, support for autodetected line endings (LF/CRLF).
+//   Also, exists on Windows MSYS2 where there isn't a getdelim.
+// * Line-length reuses previous length for initial buffer-size allocation. Pass MLR_ALLOC_READ_LINE_INITIAL_SIZE
+//   on first call. On subsequent calls, buffer-size allocations will adapt to the file's line-lengths.
 
 #define MLR_ALLOC_READ_LINE_INITIAL_SIZE 128
 
diff --git a/c/todo.txt b/c/todo.txt
index ab5e71c49..402c654a9 100644
--- a/c/todo.txt
+++ b/c/todo.txt
@@ -38,18 +38,8 @@ MSYS2 TO-DO
 
 ! msys2 / pacman -S / etc @ appveyor
 
-* getdelim replacement:
-  - comments @ header file
-  k push it into the stdio lrec readers
-  k rid of local_getdelim
-  ! experimental/getlines !
-
-k get_unlocked / getc:
-  k @ mlr_arch.h: ifdef MSYS2 define getc_unlocked(x) getc(x)
-
-k mman/mmap ifdef out entirely with default --no-mmap.
-  k @ mlr_arch.h: ifdef MSYS2 undef ENABLE_MMAP
-  k @ callsites: ifdef ENABLE_MMAP
+! MLR_ON_MSYS2: needs autocreate from ./configure or some such
+! -lpcreposix at Makefile.am: needs autocreate from ./configure or some such
 
 * setenv w/o gmtime_r
   - @ mlr_arch.h: ifdef MSYS2 undef ENABLE_SETENV
@@ -61,9 +51,6 @@ k mman/mmap ifdef out entirely with default --no-mmap.
   - @ mlr_arch_unixish: as now
   - @ mlr_arch_msys2: do it that new way. or fatal until then ... or "unimpl" retval.
 
-* -lpcreposix
-  - found how to do this in ./configure, Makefile.am w/ ifdef, something ...
-
 * needs-DLL issue:
   - find out how to fix at ./configure / msys2 build