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CPM OPERATING SYSTEMS/CPM 68K/1.0X SOURCES/v103/clib/getchar.c

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+
+/*
+	Copyright 1983
+	Alcyon Corporation
+	8716 Production Ave.
+	San Diego, CA  92121
+
+	@(#) getchar.c - Sep 12, 1983  REGULUS 4.1
+*/
+
+/* v6 getchar routine */
+
+#define BSIZE 512
+
+struct iob {
+	int fd;		/* file descriptor */
+	int cc;		/* char count */
+	char *cp;	/* ptr to next character */
+	char cbuf[BSIZE];	/* char buffer */
+} fin;
+
+getchar()
+{
+	char c;
+	register int i;
+
+	if (fin.fd == 0) {
+		if (read(0,&c,1) <= 0 || c==4)
+			return(0);
+		i = c;
+		return(i & 0xff);
+	}
+	if (fin.cc <= 0) {
+		fin.cp = &(fin.cbuf[0]);
+		fin.cc = read(fin.fd,fin.cp,BSIZE);
+	}
+	if (fin.cc <= 0)
+		return(0);
+	fin.cc--;
+	i = *(fin.cp)++;
+	return(i & 0xff);
+}
+
+