+/* Return 1 if STRING comprises a valid alias name. The shell accepts
+ essentially all characters except those which must be quoted to the
+ parser (which disqualifies them from alias expansion anyway) and `/'. */
+int
+legal_alias_name (string, flags)
+ char *string;
+ int flags;
+{
+ register char *s;
+
+ for (s = string; *s; s++)
+ if (shellbreak (*s) || shellxquote (*s) || shellexp (*s) || (*s == '/'))
+ return 0;
+ return 1;
+}
+
+/* Returns non-zero if STRING is an assignment statement. The returned value
+ is the index of the `=' sign. */
+int
+assignment (string, flags)
+ const char *string;
+ int flags;
+{
+ register unsigned char c;
+ register int newi, indx;
+
+ c = string[indx = 0];
+
+#if defined (ARRAY_VARS)
+ if ((legal_variable_starter (c) == 0) && (flags == 0 || c != '[')) /* ] */
+#else
+ if (legal_variable_starter (c) == 0)
+#endif
+ return (0);
+
+ while (c = string[indx])
+ {
+ /* The following is safe. Note that '=' at the start of a word
+ is not an assignment statement. */
+ if (c == '=')
+ return (indx);
+
+#if defined (ARRAY_VARS)
+ if (c == '[')
+ {
+ newi = skipsubscript (string, indx);
+ if (string[newi++] != ']')
+ return (0);
+ if (string[newi] == '+' && string[newi+1] == '=')
+ return (newi + 1);
+ return ((string[newi] == '=') ? newi : 0);
+ }
+#endif /* ARRAY_VARS */
+
+ /* Check for `+=' */
+ if (c == '+' && string[indx+1] == '=')
+ return (indx + 1);
+
+ /* Variable names in assignment statements may contain only letters,
+ digits, and `_'. */
+ if (legal_variable_char (c) == 0)
+ return (0);
+
+ indx++;
+ }
+ return (0);
+}
+