csv

commit ba408993ea59685a9be3d9bc837f31c2ec45e47e
parent 25a9500caba30aeb01ed4e8931a82dc6ae1efde1
Author: aabacchus <ben@bvnf.space>
Date:   Sat,  2 Oct 2021 20:10:35 +0100

use csv struct and create/destroy functions

Diffstat:
M
csv.c
 | 
81
++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------

1 file changed, 56 insertions(+), 25 deletions(-)
diff --git a/csv.c b/csv.c
@@ -6,13 +6,52 @@
 
 #define MAX_LINE 2048
 
+struct csv {
+	int cols, rows;
+	char **headers; /* array of strings */
+	float **data;  /* array of arrays of floats */
+};
+
+struct csv *
+csv_create(void) {
+	struct csv *c;
+	c = malloc(sizeof c + sizeof(char *) + sizeof(float *));
+	if (c == NULL)
+		return NULL;
+
+	c->cols = 0;
+	c->rows = 0;
+
+	char **h = malloc(sizeof (char *) * MAX_LINE);
+	if (h == NULL)
+		return NULL;
+	c->headers = h;
+
+	float **d = malloc(sizeof (float *));
+	if (d == NULL)
+		return NULL;
+	c->data = d;
+
+	return c;
+}
+
+void
+csv_destroy(struct csv *c) {
+	int i;
+	for (i = 0; i < c->cols; i++)
+		free(c->headers[i]);
+	for (i = 0; i < c->rows; i++)
+		free(c->data[i]);
+	free(c);
+}
+
 /* read_header reads each header field name from the first line of the file
  * into *header, and returns the number of columns.
  * This function mallocs the returned value of fields in *header[0..n-1]
  */
 int
-read_header(FILE *f, char ***header) {
-	char **headerp = *header;
+read_header(FILE *f, char **header) {
+	char **headerp = header;
 	int c;
 	int ncols = 0;
 	char *n = malloc(MAX_LINE);
@@ -20,7 +59,7 @@ read_header(FILE *f, char ***header) {
 	while ((c = fgetc(f)) != EOF) {
 		if (c == ',' || c == '\n') {
 			*np++ = '\0';
-			*headerp = malloc(sizeof n * sizeof *n);
+			*headerp = malloc(strlen(n));
 			strcpy(*headerp, n);
 			headerp++;
 			np = n;
@@ -112,7 +151,6 @@ cleanup:
 	free(n);
 	for (int i = 0; i < nrows; y++)
 		free(data[i]);
-	free(data);
 	return -1;
 }
 
@@ -132,8 +170,7 @@ main(int argc, char **argv) {
 	if (argc - optind > 1) {
 usage:
 		fprintf(stderr,
-			"usage: %s [-H] [file]\n  if no filename given, data is \
-read from stdin\n"
+			"usage: %s [-H] [file]\n  if no filename given, data is read from stdin\n"
 			"  -H\tread data headers from first line\n", argv[0]);
 		return 1;
 	}
@@ -150,16 +187,15 @@ read from stdin\n"
 
 	int ncols = 0;
 
+	struct csv *csv = csv_create();
+
 	if (flag_H) {
 		/* read header */
-		char **header = malloc(sizeof (char *) * MAX_LINE);
-		ncols = read_header(f, &header);
+		ncols = read_header(f, csv->headers);
 		for (int i = 0; i < ncols; i++) {
-			printf("%s\t", header[i]);
-			free(header[i]);
+			printf("%s\t", csv->headers[i]);
 		}
 		printf("\n");
-		free(header);
 	} else {
 		/* scan the first line to get the value of ncols */
 		while ((c = fgetc(f)) != EOF) {
@@ -172,29 +208,24 @@ read from stdin\n"
 		/* ensure we can properly scan the first line when we come to it */
 		rewind(f);
 	}
+	csv->cols = ncols;
 
 	/* read data */
-	float **data = malloc(sizeof (float *) * 1);
-	if (data == NULL) {
-		perror("malloc");
-		return 1;
-	}
-	int nrows = read_data(f, &data, ncols);
+	int nrows = read_data(f, &csv->data, ncols);
+	fclose(f);
 	if (nrows == -1) {
-		free(data);
-		fclose(f);
+		csv_destroy(csv);
 		return 1;
 	}
 	for (int i = 0; i < nrows; i++) {
 		for (int j = 0; j < ncols; j++)
-			printf("%g\t", data[i][j]);
+			printf("%g\t", csv->data[i][j]);
 		printf("\n");
 	}
-	fprintf(stderr, "table has %d rows of %d columns\n", nrows, ncols);
+	csv->rows = nrows;
+	fprintf(stderr, "table has %d rows of %d columns\n", csv->rows, csv->cols);
+
+	csv_destroy(csv);
 
-	for (int i = 0; i < nrows; i++)
-		free(data[i]);
-	free(data);
-	fclose(f);
 	return 0;
 }