1 files changed, 155 insertions, 0 deletions
diff --git a/reference/C/CONTRIB/SNIP/speed.c b/reference/C/CONTRIB/SNIP/speed.c
new file mode 100755
index 0000000..db77f05
--- /dev/null
+++ b/reference/C/CONTRIB/SNIP/speed.c
@@ -0,0 +1,155 @@
+/******** CALCULATE I/O PERFORMANCE TO NUL FILE ********/
+
+#include <assert.h>
+#include <dos.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define CHK     100             /* speed factor */
+
+long ticks(long tick)                                   /* GET BIOS TIME TICK */
+{
+        union REGS reg;
+        reg.h.ah=0;
+        int86(0x1A, &reg, &reg);
+        return ((long)reg.x.cx<<16)+reg.x.dx-tick;
+}
+
+long time_it(void(*func)(void))
+{
+        long t = ticks(0L);
+        (*func)();
+        return ticks(t);
+}
+
+void show_it(long t)
+{
+        long lquot, lrem;
+        t = (t*1000/182+5)/10;
+        lquot = t/10;
+        lrem = t%10;
+        printf("%3ld.%02d sec", lquot, (int)lrem);
+}
+
+void t_printf(void)
+{
+        register FILE *fp;
+        register unsigned u;
+
+        fp = fopen("NUL", "wt");
+        assert(fp != NULL);
+        for (u=0; u<50*CHK; ++u)
+                fprintf(fp, "Now is %d time for %d little indians\n", 123, -456);
+        fclose(fp);
+}
+
+void b_printf(void)
+{
+        register FILE *fp;
+        register unsigned u;
+
+        fp = fopen("NUL", "wb");
+        assert(fp != NULL);
+        for (u=0; u<50*CHK; ++u)
+                fprintf(fp, "Now is %d time for %d little indians\n", 123, -456);
+        fclose(fp);
+}
+
+void tu_printf(void)
+{
+        register FILE *fp;
+        register unsigned u;
+
+        fp = fopen("NUL", "wt");
+        assert(fp != NULL);
+        setbuf(fp, NULL);
+        for (u=0; u<5*CHK; ++u)
+                fprintf(fp, "Now is %d time for %d little indians\n", 123, -456);
+        fclose(fp);
+}
+
+void bu_printf(void)
+{
+        register FILE *fp;
+        register unsigned u;
+
+        fp = fopen("NUL", "wb");
+        assert(fp != NULL);
+        setbuf(fp, NULL);
+        for (u=0; u<5*CHK; ++u)
+                fprintf(fp, "Now is %d time for %d little indians\n", 123, -456);
+        fclose(fp);
+}
+
+void t_write(void)
+{
+        register FILE *fp;
+        register unsigned u;
+
+        fp = fopen("NUL", "wt");
+        assert(fp != NULL);
+        for (u=0; u<250*CHK; ++u)
+                fwrite("Now is the time for all good men to come\n", 41, 1, fp);
+        fclose(fp);
+}
+
+void b_write(void)
+{
+        register FILE *fp;
+        register unsigned u;
+
+        fp = fopen("NUL", "wb");
+        assert(fp != NULL);
+        for (u=0; u<500*CHK; ++u)
+                fwrite("Now is the time for all good men to come\n", 41, 1, fp);
+        fclose(fp);
+}
+
+void tu_write(void)
+{
+        register FILE *fp;
+        register unsigned u;
+
+        fp = fopen("NUL", "wt");
+        assert(fp != NULL);
+        setbuf(fp, NULL);
+        for (u=0; u<100*CHK; ++u)
+                fwrite("Now is the time for all good men to come\n", 41, 1, fp);
+        fclose(fp);
+}
+
+void bu_write(void)
+{
+        register FILE *fp;
+        register unsigned u;
+
+        fp = fopen("NUL", "wb");
+        assert(fp != NULL);
+        setbuf(fp, NULL);
+        for (u=0; u<200*CHK; ++u)
+                fwrite("Now is the time for all good men to come\n", 41, 1, fp);
+        fclose(fp);
+}
+
+main(void)
+{
+        show_it(time_it(t_printf));
+        printf(": time for text printf buffered\n");
+        show_it(time_it(b_printf));
+        printf(": time for binary printf buffered\n");
+        show_it(time_it(tu_printf));
+        printf(": time for text printf unbuffered\n");
+        show_it(time_it(bu_printf));
+        printf(": time for binary printf unbuffered\n");
+
+        show_it(time_it(t_write));
+        printf(": time for text write buffered\n");
+        show_it(time_it(b_write));
+        printf(": time for binary write buffered\n");
+        show_it(time_it(tu_write));
+        printf(": time for text write unbuffered\n");
+        show_it(time_it(bu_write));
+        printf(": time for binary write unbuffered\n");
+
+        return 0;
+}