4.38 getline—read a line from a file

Synopsis

#include <stdio.h>
ssize_t getline(char **bufptr, size_t *n, FILE *fp);

Description
getline reads a file fp up to and possibly including the newline character. The line is read into a buffer pointed to by bufptr and designated with size *n. If the buffer is not large enough, it will be dynamically grown by getdelim. As the buffer is grown, the pointer to the size n will be updated.

getline is equivalent to getdelim(bufptr, n, ’\n’, fp);

Returns
getline returns -1 if no characters were successfully read, otherwise, it returns the number of bytes successfully read. at end of file, the result is nonzero.

Portability
getline is a glibc extension.

No supporting OS subroutines are directly required.