file.c

#include <stdio.h>

#include "util.h"
#include "file.h"
#include "vec.h"

#define STEP 256

/* vbuf is a vector */
int read_line_v(FILE *f, char *vbuf)
{
    int err = 0;
    size_t idx = 0;
    size_t bytes;

    vec__reserve(vbuf, STEP);

    while ((bytes = fread(__vec__at(vbuf, idx), vec__mem_size(vbuf), min(vec__cap(vbuf) - idx, STEP), f))) {
        size_t pre_idx = idx;
        char *vbuf_raw = NULL;

        idx += bytes;
        vec__len_inc(vbuf, bytes / vec__mem_size(vbuf));

        /* check if there's a newline */
        vbuf_raw = __vec__at(vbuf, 0);
        for (size_t i = pre_idx; i < idx; i++) {
            if (vbuf_raw[i] == '\n') {
                size_t new_size = i / vec__mem_size(vbuf);

                vec__resize(vbuf, new_size);
                goto read_out;
            }
        }

        if (vec__cap(vbuf) == idx) {
            if (vec__alloc(vbuf, STEP))
                return -1;
        }
    }

read_out:
    // insert null term
    if (vec__cap(vbuf) >= vec__len(vbuf) + 1)
        ((char *)__vec__at(vbuf, 0))[vec__len(vbuf)] = 0;
    else
        *((char *)__vec__at(vbuf, vec__cap(vbuf) - 1)) = '\0';

    pr_debug("Read line: \" %s \"\n", (char *)__vec__at(vbuf, 0));
    return 0;
}