Implement csv_save().

src/csv-data-manipulation.c

@@ -17,13 +17,16 @@
 
 
 typedef struct {
-	char delim;
+	char * delim;
 	unsigned int rows;
 	unsigned int cols;
 	char ** table;
 } CSV;
 
-/* trim whitespaces from left & right of a string */
+
+/** 
+ * Utility function to trim whitespaces from left & right of a string
+ */
 int trim(char ** str) {
 	int trimmed;
 	int n;
@@ -49,20 +52,40 @@ int trim(char ** str) {
 	return trimmed;
 }
 
-CSV * csv_create() {
+
+/** 
+ * De-allocate csv structure 
+ */
+int csv_destroy(CSV * csv) {
+	if (csv == NULL) { return 0; }
+	if (csv->table != NULL) { free(csv->table); }
+	if (csv->delim != NULL) { free(csv->delim); }
+	free(csv);
+	return 0;
+}
+
+
+/**
+ * Allocate memory for a CSV structure 
+ */
+CSV * csv_create(unsigned int cols, unsigned int rows) {
 	CSV * csv;
 	
 	csv = malloc(sizeof(CSV));
-	csv->rows = 0;
-	csv->cols = 0;
-	csv->table = NULL;
+	csv->rows = rows;
+	csv->cols = cols;
+	csv->delim = strdup(",");
+
+	csv->table = malloc(sizeof(char *) * cols * rows);
+	if (csv->table == NULL) { goto error; }
+
+	memset(csv->table, 0, sizeof(char *) * cols * rows);
 
 	return csv;
-}
 
-int csv_destroy(CSV * csv) {
-	free(csv);
-	return 0;
+error:
+	csv_destroy(csv);
+	return NULL;
 }
 
 
@@ -70,7 +93,9 @@ int csv_destroy(CSV * csv) {
  * Get value in CSV table at COL, ROW
  */
 char * csv_get(CSV * csv, unsigned int col, unsigned int row) {
-	return NULL;
+	unsigned int idx;
+	idx = col + (row * csv->cols);
+	return csv->table[idx];
 }
 
 
@@ -78,9 +103,32 @@ char * csv_get(CSV * csv, unsigned int col, unsigned int row) {
  * Set value in CSV table at COL, ROW
  */
 int csv_set(CSV * csv, unsigned int col, unsigned int row, char * value) {
+	unsigned int idx;
+	idx = col + (row * csv->cols);
+	csv->table[idx] = value;
 	return 0;
 }
 
+void csv_display(CSV * csv) {
+	int row, col;
+	char * content;
+	if ((csv->rows == 0) || (csv->cols==0)) {
+		printf("[Empty table]\n");
+		return ;
+	}
+
+	printf("\n[Table cols=%d rows=%d]\n", csv->cols, csv->rows);
+	for (row=0; row<csv->rows; row++) {
+		printf("[|");
+		for (col=0; col<csv->cols; col++) {
+			content = csv_get(csv, col, row);
+            printf("%s\t|", content);
+		}
+        printf("]\n");
+	}
+	printf("\n");
+}
+
 /* Resize CSV table
  * - grow columns: on each row, add missing columns cells 
  * - grow rows: add now rows, with all columns count
@@ -97,14 +145,12 @@ int csv_resize(CSV * old_csv, unsigned int new_cols, unsigned int new_rows) {
 	bool in_old, in_new;
 
 	/* Build a new (fake) csv */
-	new_csv = csv_create();
+	new_csv = csv_create(new_cols, new_rows);
+	if (new_csv == NULL) { goto error; }
+
 	new_csv->rows = new_rows;
 	new_csv->cols = new_cols;
 
-	new_csv->table = malloc(sizeof(char *) * new_cols * new_rows);
-	memset(new_csv->table, 0, sizeof(char *) * new_cols * new_rows);
-
-	if (new_csv->table == NULL) { goto error; }
 
 	max_cols = (new_cols > old_csv->cols)? new_cols : old_csv->cols;
 	max_rows = (new_rows > old_csv->rows)? new_rows : old_csv->rows;
@@ -122,10 +168,7 @@ int csv_resize(CSV * old_csv, unsigned int new_cols, unsigned int new_rows) {
 				/* destroy data */
 				content = csv_get(old_csv, cur_col, cur_row);
 				free(content);
-			} else { 
-				/* skip */
-				/* csv_set(new_csv, cur_col, cur_row, NULL); */
-			}
+			} else { /* skip */ }
 		}
 	}
 	/* on rows */		
@@ -133,6 +176,9 @@ int csv_resize(CSV * old_csv, unsigned int new_cols, unsigned int new_rows) {
 	old_csv->rows = new_rows;
 	old_csv->cols = new_cols;
 	old_csv->table = new_csv->table;
+	new_csv->table = NULL;
+	csv_destroy(new_csv);
+
 	return 0;
 
 error:
@@ -151,34 +197,52 @@ int csv_open(CSV * csv, char * filename) {
 
 
 	fp = fopen(filename, "r");
-	if (fp == NULL) { exit(EXIT_FAILURE); }
+	if (fp == NULL) { goto error; }
 
 	m_rows = 0;
 	m_cols = 0;
 	while(fgets(line, sizeof(line), fp) != NULL) {
- 		/* printf("Got line: %s", line); */
  		m_rows += 1;
  		cols = 0;
  		lineptr = line;
- 		while ((token = strtok(lineptr, ",")) != NULL) {
+ 		while ((token = strtok(lineptr, csv->delim)) != NULL) {
  			lineptr = NULL;
  			trim(&token);
-            printf("%s\t|", token);
             cols += 1;
         	if (cols > m_cols) { m_cols = cols; }
             csv_resize(csv, m_cols, m_rows);
+            csv_set(csv, cols-1, m_rows-1, strdup(token));
         }
-        printf("\n");
 	}
 
 	fclose(fp);
-	csv->delim = '\t';
 	csv->rows = m_rows;
 	csv->cols = m_cols;
 	return 0;
+
+error:
+	fclose(fp);
+	printf("Unable to open %s for reading.", filename);
+	return -1;
 }
 
+
 int csv_save(CSV * csv, char * filename) {
+	FILE * fp;
+	int row, col;
+	char * content;
+
+	fp = fopen(filename, "w");
+	for (row=0; row<csv->rows; row++) {
+		for (col=0; col<csv->cols; col++) {
+			content = csv_get(csv, col, row);
+            fprintf(fp, "%s%s", content, 
+            		((col == csv->cols-1) ? "" : csv->delim) );
+		}
+        fprintf(fp, "\n");
+	}
+
+	fclose(fp);
 	return 0;
 }
 
@@ -187,17 +251,18 @@ int main(int argc, char ** argv) {
 
 	printf("%s\n%s\n\n",TITLE, URL);
 
-
-	csv = csv_create();
+	csv = csv_create(0, 0);
 	csv_open(csv, "fixtures/csv-data-manipulation.csv");
+	csv_display(csv);
 
 	csv_set(csv, 0, 0, "Column0");
 	csv_set(csv, 1, 1, "100");
 	csv_set(csv, 2, 2, "200");
 	csv_set(csv, 3, 3, "300");
 	csv_set(csv, 4, 4, "400");
+	csv_display(csv);
 
-	csv_save(csv, "fixtures/csv-data-manupulation.out.csv");
+	csv_save(csv, "tmp/csv-data-manupulation.out.csv");
 	csv_destroy(csv);
 
 	return 0;