parse_lsn.c

#include <stdlib.h>
#include "parse_lsn.h"

#define skipws(p)                                                              \
    {                                                                          \
        while (*p != '\0' && *p == ' ')                                        \
            p++;                                                               \
    }
#define isnum(p) (*p >= '0' && *p <= '9')

int char_to_lsn(const char *lsnstr, unsigned int *file, unsigned int *offset)
{
    const char *p = lsnstr;
    while (*p != '\0' && *p == ' ')
        p++;
    skipws(p);

    /* Parse opening '{' */
    if (*p != '{')
        return -1;
    p++;
    skipws(p);
    if (!isnum(p))
        return -1;

    /* Parse file */
    *file = (unsigned int)atol(p);
    while (isnum(p))
        p++;
    skipws(p);
    if (*p != ':')
        return -1;
    p++;
    skipws(p);
    if (!isnum(p))
        return -1;

    /* Parse offset */
    *offset = (unsigned int)atol(p);
    while (isnum(p))
        p++;

    skipws(p);

    /* Parse closing '}' */
    if (*p != '}')
        return -1;
    p++;

    skipws(p);
    if (*p != '\0')
        return -1;

    return 0;
}