Page 164 - C-Language

{
int c;
while (EOF != (c = getc(fin)))
{
/* Note we read a character. */
num_read++;

/* Reallocate the buffer if we need more room */
if (num_read >= *pn)
{
size_t n_realloc = *pn + ALLOCSTEP;
char * tmp = realloc(*pline_buf, n_realloc + 1); /* +1 for the trailing NUL. */
if (NULL != tmp)
{
/* Use the new buffer and note the new buffer size. */
*pline_buf = tmp;
*pn = n_realloc;
}
else
{
/* Exit with error and let the caller free the buffer. */
return -1;
}

/* Test for overflow. */
if (SSIZE_MAX < *pn)
{
errno = ERANGE;
return -1;
}
}

/* Add the character to the buffer. */
(*pline_buf)[num_read - 1] = (char) c;

/* Break from the loop if we hit the ending character. */
if (c == '\n')
{
break;
}
}

/* Note if we hit EOF. */
if (EOF == c)
{
errno = 0;
return -1;
}
}

/* Terminate the string by suffixing NUL. */
(*pline_buf)[num_read] = '\0';

return (ssize_t) num_read;
}

#endif

Open and write to a binary file

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