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#include <stdio.h>
#include <string.h>
#include <zsv.h>
/**
* Simple example using libzsv as a pull parser for CSV input
*
* This is the same as simple.c, but uses pull parsing instead of push parsing
*
* We will check each cell in the row to determine if it is blank, and output
* the row number, the total number of cells and the number of blank cells
*
* Example:
* `echo 'abc,def\nghi,,,' | build/simple -`
* Outputs:
* Row 1 has 2 columns of which 0 are non-blank
* Row 2 has 4 columns of which 3 are non-blank
*
* With pull parsing, the parser just repeatedly calls zsv_next_row() so long
* as it returns `zsv_status_row`
*/
/**
* Main routine. Our program will take a single argument (a file name, or -)
* and output, for each row, the numbers of total and blank cells
*/
int main(int argc, const char *argv[]) {
if (argc != 2) {
fprintf(stderr, "Reads a CSV file or stdin, and for each row,\n"
" output counts of total and blank cells\n");
fprintf(stderr, "Usage: simple <filename or dash(-) for stdin>\n");
fprintf(stderr,
"Example:\n"
" echo \"A1,B1,C1\\nA2,B2,\\nA3,,C3\\n,,C3\" | %s -\n\n",
argv[0]);
return 0;
}
FILE *f = strcmp(argv[1], "-") ? fopen(argv[1], "rb") : stdin;
if (!f) {
perror(argv[1]);
return 1;
}
/**
* Create a parser
*/
struct zsv_opts opts = {0};
opts.stream = f;
zsv_parser parser = zsv_new(&opts);
if (!parser) {
fprintf(stderr, "Could not allocate parser!\n");
return -1;
}
/**
* iterate through all rows
*/
size_t row_num = 0;
while (zsv_next_row(parser) == zsv_status_row) {
row_num++;
/* get a cell count */
size_t cell_count = zsv_cell_count(parser);
/* iterate through each cell in this row, to count blanks */
size_t nonblank = 0;
for (size_t i = 0; i < cell_count; i++) {
struct zsv_cell c = zsv_get_cell(parser, i);
/* use r.values[] and r.lengths[] to get cell data */
/* Here, we only care about lengths */
if (c.len > 0)
nonblank++;
}
/* print our results for this row */
printf("Row %zu has %zu columns of which %zu %s non-blank\n", row_num, cell_count, nonblank,
nonblank == 1 ? "is" : "are");
}
/**
* Clean up
*/
zsv_delete(parser);
if (f != stdin)
fclose(f);
return 0;
}
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