New commandline/script parser, supports backslash quoting and environment

variable substitution.

Submitted by:	Jordan Hubbard <jkh@freebsd.org>

1 files changed, 157 insertions, 0 deletions

diff --git a/sys/boot/common/interp_backslash.c b/sys/boot/common/interp_backslash.c
new file mode 100644
index 0000000..cbabb7c
--- /dev/null
+++ b/sys/boot/common/interp_backslash.c
@@ -0,0 +1,157 @@
+/*
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * Jordan K. Hubbard
+ * 29 August 1998
+ *
+ *	$Id$
+ *
+ * Routine for doing backslash elimination.
+ */
+
+#include <stand.h>
+#include <string.h>
+
+#define DIGIT(x) (isdigit(x) ? (x) - '0' : islower(x) ? (x) + 10 - 'a' : (x) + 10 - 'A')
+
+/*
+ * backslash: Return malloc'd copy of str with all standard "backslash
+ * processing" done on it.  Original can be free'd if desired.
+ */
+char *
+backslash(char *str)
+{
+    /*
+     * Remove backslashes from the strings. Turn \040 etc. into a single
+     * character (we allow eight bit values). Currently NUL is not
+     * allowed.
+     *
+     * Turn "\n" and "\t" into '\n' and '\t' characters. Etc.
+     *
+     */
+    char *new_str;
+    int seenbs = 0;
+    int i = 0;
+
+    if ((new_str = strdup(str)) == NULL)
+	return NULL;
+
+    while (*str) {
+	if (seenbs) {
+	    seenbs = 0;
+	    switch (*str) {
+	    case '\\':
+		new_str[i++] = '\\';
+		str++;
+		break;
+
+	    case 'b':
+		new_str[i++] = '\b';
+		str++;
+		break;
+
+	    case 'f':
+		new_str[i++] = '\f';
+		str++;
+		break;
+
+	    case 'r':
+		new_str[i++] = '\r';
+		str++;
+		break;
+
+	    case 'n':
+		new_str[i++] = '\n';
+		str++;
+		break;
+
+	    case 's':
+		new_str[i++] = ' ';
+		str++;
+		break;
+
+	    case 't':
+		new_str[i++] = '\t';
+		str++;
+		break;
+
+	    case 'v':
+		new_str[i++] = '\13';
+		str++;
+		break;
+
+	    case 'z':
+		str++;
+		break;
+
+	    case '0': case '1': case '2': case '3': case '4':
+	    case '5': case '6': case '7': case '8': case '9': {
+		char val;
+
+		/* Three digit octal constant? */
+		if (*str >= '0' && *str <= '3' && 
+		    *(str + 1) >= '0' && *(str + 1) <= '7' &&
+		    *(str + 2) >= '0' && *(str + 2) <= '7') {
+
+		    val = (DIGIT(*str) << 6) + (DIGIT(*(str + 1)) << 3) + 
+			DIGIT(*(str + 2));
+
+		    /* Allow null value if user really wants to shoot
+                       at feet, but beware! */
+		    new_str[i++] = val;
+		    str += 3;
+		    break;
+		}
+
+		/* One or two digit hex constant?
+		 * If two are there they will both be taken.
+		 * Use \z to split them up if this is not wanted.
+		 */
+		if (*str == '0' &&
+		    (*(str + 1) == 'x' || *(str + 1) == 'X') &&
+		    isxdigit(*(str + 2))) {
+		    val = DIGIT(*(str + 2));
+		    if (isxdigit(*(str + 3))) {
+			val = (val << 4) + DIGIT(*(str + 3));
+			str += 4;
+		    }
+		    else
+			str += 3;
+		    /* Yep, allow null value here too */
+		    new_str[i++] = val;
+		    break;
+		}
+	    }
+	    break;
+
+	    default:
+		new_str[i++] = *str++;
+		break;
+	    }
+	}
+        else {
+            if (*str == '\\') {
+                seenbs = 1;
+                str++;
+            }
+	    else
+		new_str[i++] = *str++;
+        }
+    }
+
+    if (seenbs) {
+        /*
+         * The final character was a '\'. Put it in as a single backslash.
+         */
+	new_str[i++] = '\\';
+    }
+    new_str[i] = '\0';
+    return new_str;
+}