al_fget_ustr man page
al_fget_ustr — Allegro 5 API
#include <allegro5/allegro.h> ALLEGRO_USTR *al_fget_ustr(ALLEGRO_FILE *f)
Read a string of bytes terminated with a newline or end-of-file. The line terminator(s), if any, are included in the returned string.
On success returns a pointer to a new ALLEGRO_USTR structure. This must be freed eventually with al_ustr_free(3). Returns NULL if an error occurred or if the end of file was reached without reading any bytes.
See al_fopen(3) about translations of end-of-line characters.