Page 162 - C-Language

{
/* Increment our line count */
line_count++;

/* Show the line details */
printf("line[%06d]: chars=%06zd, buf size=%06zu, contents: %s", line_count,
line_size, line_buf_size, line_buf);

/* Get the next line */
line_size = getline(&line_buf, &line_buf_size, fp);
}

/* Free the allocated line buffer */
free(line_buf);
line_buf = NULL;

/* Close the file now that we are done with it */
fclose(fp);

return EXIT_SUCCESS;
}

Input file example.txt

This is a file
which has
multiple lines
with various indentation,
blank lines

a really long line to show that getline() will reallocate the line buffer if the length of a
line is too long to fit in the buffer it has been given,
and punctuation at the end of the lines.

Output

line[000001]: chars=000015, buf size=000016, contents: This is a file
line[000002]: chars=000012, buf size=000016, contents: which has
line[000003]: chars=000015, buf size=000016, contents: multiple lines
line[000004]: chars=000030, buf size=000032, contents: with various indentation,
line[000005]: chars=000012, buf size=000032, contents: blank lines
line[000006]: chars=000001, buf size=000032, contents:
line[000007]: chars=000001, buf size=000032, contents:
line[000008]: chars=000001, buf size=000032, contents:
line[000009]: chars=000150, buf size=000160, contents: a really long line to show that
getline() will reallocate the line buffer if the length of a line is too long to fit in the
buffer it has been given,
line[000010]: chars=000042, buf size=000160, contents: and punctuation at the end of the
lines.
line[000011]: chars=000001, buf size=000160, contents:

In the example, getline() is initially called with no buffer allocated. During this first call, getline()
allocates a buffer, reads the first line and places the line's contents in the new buffer. On
subsequent calls, getline() updates the same buffer and only reallocates the buffer when it is no

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