/* eofeoln.c: implement Pascal's ideas for end-of-file and end-of-line testing. Public domain. */ #include #include "lib.h" /* Return true if we're at the end of FILE, else false. This implements Pascal's `eof' builtin. */ boolean eof (FILE *file) { register int c; /* If FILE doesn't exist, return true. This happens, for example, when a user does `mft foo.mf' -- there's no change file, so we never open it, so we end up calling this with a null pointer. */ if (!file) return true; /* Maybe we're already at the end? */ if (feof (file)) return true; if ((c = getc (file)) == EOF) return true; /* We weren't at the end. Back up. */ (void) ungetc (c, file); return false; } /* Return true on end-of-line in FILE or at the end of FILE, else false. */ /* Accept both CR and LF as end-of-line. */ boolean eoln (FILE *file) { register int c; if (feof (file)) return true; c = getc (file); if (c != EOF) (void) ungetc (c, file); return c == '\n' || c == '\r' || c == EOF; } /* Consume input up and including the first eol encountered. */ /* Handle CRLF as a single end-of-line. */ void readln (FILE *f) { int c; while ((c = getc (f)) != '\n' && c != '\r' && c != EOF) ; if (c == '\r' && (c = getc (f)) != '\n' && c != EOF) ungetc (c, f); }