Initial revision

diff --git a/src/internat.c b/src/internat.c
new file mode 100644 (file)
index 0000000..59a508a
--- /dev/null
+++ b/src/internat.c
@@ -0,0 +1,72 @@
+#include "file.h"
+
+#include <string.h>
+
+#define F 0
+#define T 1
+
+/*
+ * List of characters that look "reasonable" in international
+ * language texts.  That's almost all characters :), except a
+ * few in the control range of ASCII (all the known international
+ * charactersets share the bottom half with ASCII).
+ */
+static char maybe_internat[256] = {
+       F, F, F, F, F, F, F, F, T, T, T, T, T, T, F, F,  /* 0x0X */
+       F, F, F, F, F, F, F, F, F, F, F, T, F, F, F, F,  /* 0x1X */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x2X */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x3X */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x4X */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x5X */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x6X */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, F,  /* 0x7X */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x8X */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x9X */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0xaX */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0xbX */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0xcX */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0xdX */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0xeX */
+       T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T   /* 0xfX */
+};
+
+/* Maximal length of a line we consider "reasonable". */
+#define MAXLINELEN 300
+
+int
+internatmagic(buf, nbytes)
+       unsigned char *buf;
+       int nbytes;
+{
+       int i;
+       unsigned char *cp;
+
+       nbytes--;
+
+       /* First, look whether there are "unreasonable" characters. */
+       for (i = 0, cp = buf; i < nbytes; i++, cp++)
+               if (!maybe_internat[*cp])
+                       return 0;
+
+       /*
+        * Now, look whether the file consists of lines of
+        * "reasonable" length.
+        */
+
+       for (i = 0; i < nbytes;) {
+               cp = memchr(buf, '\n', nbytes - i);
+               if (cp == NULL) {
+                       /* Don't fail if we hit the end of buffer. */
+                       if (i + MAXLINELEN >= nbytes)
+                               break;
+                       else
+                               return 0;
+               }
+               if (cp - buf > MAXLINELEN)
+                       return 0;
+               i += (cp - buf + 1);
+               buf = cp + 1;
+       }
+       ckfputs("International language text", stdout);
+       return 1;
+}