csv

commit c13189446dd8f040b669db70ea5fd93a62959fc5
parent ba408993ea59685a9be3d9bc837f31c2ec45e47e
Author: aabacchus <ben@bvnf.space>
Date:   Sat,  2 Oct 2021 20:28:16 +0100

add csv_read_file function

Diffstat:
M
csv.c
 | 
49
+++++++++++++++++++++++++++++++------------------

1 file changed, 31 insertions(+), 18 deletions(-)
diff --git a/csv.c b/csv.c
@@ -12,6 +12,9 @@ struct csv {
 	float **data;  /* array of arrays of floats */
 };
 
+int
+csv_read_file(FILE *, struct csv *, char hdr);
+
 struct csv *
 csv_create(void) {
 	struct csv *c;
@@ -157,7 +160,7 @@ cleanup:
 int
 main(int argc, char **argv) {
 	int c;
-	int flag_H = 0;
+	char flag_H = 0;
 	while ((c = getopt(argc, argv, "Hh")) != -1) {
 		switch (c) {
 			case 'H':
@@ -174,6 +177,7 @@ usage:
 			"  -H\tread data headers from first line\n", argv[0]);
 		return 1;
 	}
+
 	FILE *f;
 	if (argc - optind == 0) {
 		f = stdin;
@@ -185,22 +189,35 @@ usage:
 		}
 	}
 
-	int ncols = 0;
-
 	struct csv *csv = csv_create();
+	if (csv == NULL) {
+		perror("csv_create");
+		return 1;
+	}
+	int ret = csv_read_file(f, csv, flag_H);
+	if (ret != 0) {
+		csv_destroy(csv);
+		return 1;
+	}
+	return 0;
+}
 
-	if (flag_H) {
+int
+csv_read_file(FILE *f, struct csv *c, char hdr) {
+	int ch;
+	int ncols = 0;
+	if (hdr) {
 		/* read header */
-		ncols = read_header(f, csv->headers);
+		ncols = read_header(f, c->headers);
 		for (int i = 0; i < ncols; i++) {
-			printf("%s\t", csv->headers[i]);
+			printf("%s\t", c->headers[i]);
 		}
 		printf("\n");
 	} else {
 		/* scan the first line to get the value of ncols */
-		while ((c = fgetc(f)) != EOF) {
-			if (c == ',') ncols++;
-			if (c == '\n') {
+		while ((ch = fgetc(f)) != EOF) {
+			if (ch == ',') ncols++;
+			if (ch == '\n') {
 				ncols++;
 				break;
 			}
@@ -208,24 +225,20 @@ usage:
 		/* ensure we can properly scan the first line when we come to it */
 		rewind(f);
 	}
-	csv->cols = ncols;
+	c->cols = ncols;
 
 	/* read data */
-	int nrows = read_data(f, &csv->data, ncols);
+	int nrows = read_data(f, &c->data, ncols);
 	fclose(f);
 	if (nrows == -1) {
-		csv_destroy(csv);
+		csv_destroy(c);
 		return 1;
 	}
 	for (int i = 0; i < nrows; i++) {
 		for (int j = 0; j < ncols; j++)
-			printf("%g\t", csv->data[i][j]);
+			printf("%g\t", c->data[i][j]);
 		printf("\n");
 	}
-	csv->rows = nrows;
-	fprintf(stderr, "table has %d rows of %d columns\n", csv->rows, csv->cols);
-
-	csv_destroy(csv);
-
+	c->rows = nrows;
 	return 0;
 }