dd: move suffix struct to xatonum.c
[oweals/busybox.git] / coreutils / expr.c
index 04d783f2b58fc21d050fdf9475abb8ef3e81a8f2..c986f93274f7e57e4070b135958c10e97df744ce 100644 (file)
 
 /* no getopt needed */
 
+//usage:#define expr_trivial_usage
+//usage:       "EXPRESSION"
+//usage:#define expr_full_usage "\n\n"
+//usage:       "Print the value of EXPRESSION to stdout\n"
+//usage:    "\n"
+//usage:       "EXPRESSION may be:\n"
+//usage:       "       ARG1 | ARG2     ARG1 if it is neither null nor 0, otherwise ARG2\n"
+//usage:       "       ARG1 & ARG2     ARG1 if neither argument is null or 0, otherwise 0\n"
+//usage:       "       ARG1 < ARG2     1 if ARG1 is less than ARG2, else 0. Similarly:\n"
+//usage:       "       ARG1 <= ARG2\n"
+//usage:       "       ARG1 = ARG2\n"
+//usage:       "       ARG1 != ARG2\n"
+//usage:       "       ARG1 >= ARG2\n"
+//usage:       "       ARG1 > ARG2\n"
+//usage:       "       ARG1 + ARG2     Sum of ARG1 and ARG2. Similarly:\n"
+//usage:       "       ARG1 - ARG2\n"
+//usage:       "       ARG1 * ARG2\n"
+//usage:       "       ARG1 / ARG2\n"
+//usage:       "       ARG1 % ARG2\n"
+//usage:       "       STRING : REGEXP         Anchored pattern match of REGEXP in STRING\n"
+//usage:       "       match STRING REGEXP     Same as STRING : REGEXP\n"
+//usage:       "       substr STRING POS LENGTH Substring of STRING, POS counted from 1\n"
+//usage:       "       index STRING CHARS      Index in STRING where any CHARS is found, or 0\n"
+//usage:       "       length STRING           Length of STRING\n"
+//usage:       "       quote TOKEN             Interpret TOKEN as a string, even if\n"
+//usage:       "                               it is a keyword like 'match' or an\n"
+//usage:       "                               operator like '/'\n"
+//usage:       "       (EXPRESSION)            Value of EXPRESSION\n"
+//usage:       "\n"
+//usage:       "Beware that many operators need to be escaped or quoted for shells.\n"
+//usage:       "Comparisons are arithmetic if both ARGs are numbers, else\n"
+//usage:       "lexicographical. Pattern matches return the string matched between\n"
+//usage:       "\\( and \\) or null; if \\( and \\) are not used, they return the number\n"
+//usage:       "of characters matched or 0."
+
 #include "libbb.h"
 #include "xregex.h"
 
@@ -65,6 +100,7 @@ struct globals {
        char **args;
 } FIX_ALIASING;
 #define G (*(struct globals*)&bb_common_bufsiz1)
+#define INIT_G() do { } while (0)
 
 /* forward declarations */
 static VALUE *eval(void);
@@ -484,6 +520,8 @@ int expr_main(int argc UNUSED_PARAM, char **argv)
 {
        VALUE *v;
 
+       INIT_G();
+
        xfunc_error_retval = 2; /* coreutils compat */
        G.args = argv + 1;
        if (*G.args == NULL) {