GETLINE(3)

NAME
getdelim, getline - get a line from a stream

LIBRARY
libc

SYNOPSIS
#include <stdio.h>
ssize_t
getdelim(char ** restrict linep, size_t * restrict linecapp, int delimiter, FILE * restrict stream);
ssize_t
getline(char ** restrict linep, size_t * restrict linecapp, FILE * restrict stream);

DESCRIPTION
The getdelim() function reads a line from stream, delimited by the character delimiter. The getline() function is equivalent to getdelim() with the newline character as the delimiter. The delimiter character is included as part of the line, unless the end of the file is reached.

The caller may provide a pointer to a malloced buffer for the line in *linep, and the capacity of that buffer in *linecapp. These functions expand the buffer as needed, as if via realloc(). If linep points to a NULL pointer, a new buffer will be allocated. In either case, *linep and *linecapp will be updated accordingly.

RETURN VALUES
The getdelim() and getline() functions return the number of characters stored in the buffer, excluding the terminating NUL character. The value -1 is returned if an error occurs, or if end-of-file is reached.

The functions do not distinguish between end-of-file and error, and callers must use feof(3) and ferror(3) to determine which occurred.

EXAMPLES
The following code fragment reads lines from a file and writes them to standard output. The fwrite() function is used in case the line contains embedded NUL characters.

    char *line = NULL;
    size_t linecap = 0;
    ssize_t linelen;
    while ((linelen = getline(&line, &linecap, fp)) > 0)
    	fwrite(line, linelen, 1, stdout);
    free(line);
    if (ferror(fp))
    	perror("getline");

ERRORS
These functions may fail if:

[EINVAL]
    Either linep or linecapp is NULL.

[EOVERFLOW]
    No delimiter was found in the first SSIZE_MAX characters.

These functions may also fail due to any of the errors specified for fgets() and malloc().

SEE ALSO
ferror(3), fgetln(3), fgets(3), malloc(3)

STANDARDS
The getdelim() and getline() functions conform to p1003.1-2008.

HISTORY
These routines first appeared in DragonFly 2.3.

BUGS
There are no wide character versions of getdelim() or getline().