Use string-no-nuls?' and bytes-no-nuls?' in more docs & error messages.

Also use `byte?' instead of (integer-in 0 255).

(This commit will most likely require some proof-reading.)

collects/scribblings/reference/subprocess.scrbl

@@ -7,7 +7,7 @@
                         [stdin (or/c (and/c input-port? file-stream-port?) #f)]
                         [stderr (or/c (and/c output-port? file-stream-port?) #f 'stdout)]
                         [command path-string?]
-                        [arg (or/c path? string? bytes?)] ...)
+                        [arg (or/c path? string-no-nuls? bytes-no-nuls?)] ...)
             (values subprocess?
                     (or/c (and/c input-port? file-stream-port?) #f)
                     (or/c (and/c output-port? file-stream-port?) #f)
@@ -217,7 +217,7 @@ interactive shell, since job control is based on process groups.}
                         [target string?]
                         [parameters string?]
                         [dir path-string?]
-                        [show-mode symbol?]) 
+                        [show-mode symbol?])
          #f]{
 
 @index['("ShellExecute")]{Performs} the action specified by @racket[verb]
@@ -318,7 +318,7 @@ real process ID).}
 
 @note-lib[racket/system]
 
-@defproc[(system [command (or/c string? bytes?)]) boolean?]{
+@defproc[(system [command (or/c string-no-nuls? bytes-no-nuls?)]) boolean?]{
 
 Executes a Unix, Mac OS X, or Windows shell command synchronously
 (i.e., the call to @racket[system] does not return until the
@@ -342,8 +342,11 @@ function:
 ]}
 
 
-@defproc*[([(system* [command path-string?] [arg (or/c path? string? bytes?)] ...) boolean?]
+@defproc*[([(system* [command path-string?]
-           [(system* [command path-string?] [exact 'exact] [arg string?]) boolean?])]{
+                     [arg (or/c path? string-no-nuls? bytes-no-nuls?)] ...)
+            boolean?]
+           [(system* [command path-string?] [exact 'exact] [arg string?])
+            boolean?])]{
 
 Like @racket[system], except that @racket[command] is a filename that
 is executed directly (instead of through a shell command; see
@@ -358,20 +361,25 @@ On Windows, the first argument after @racket[command] can be
 line. See @racket[subprocess] for details.}
 
 
-@defproc[(system/exit-code [command (or/c string? bytes?)]) (integer-in 0 255)]{
+@defproc[(system/exit-code [command (or/c string-no-nuls? bytes-no-nuls?)])
+         byte?]{
 
 Like @racket[system], except that the result is the exit code returned
 by the subprocess. A @racket[0] result normally indicates success.}
 
 
-@defproc*[([(system*/exit-code [command path-string?] [arg (or/c path? string? bytes?)] ...) (integer-in 0 255)]
+@defproc*[([(system*/exit-code [command path-string?]
-           [(system*/exit-code [command path-string?] [exact 'exact] [arg string?]) (integer-in 0 255)])]{
+                               [arg (or/c path? string-no-nuls? bytes-no-nuls?)] ...)
+            byte?]
+           [(system*/exit-code [command path-string?]
+                               [exact 'exact] [arg string?])
+            byte?])]{
 
 Like @racket[system*], but returns the exit code like
 @racket[system/exit-code].}
- 
 
-@defproc[(process [command string?])
+
+@defproc[(process [command (or/c string-no-nuls? bytes-no-nuls?)])
          (list input-port?
                output-port?
                exact-nonnegative-integer?
@@ -438,10 +446,13 @@ implement @racket[process]. In particular, the @racket['interrupt] and
 @racket['kill] process-control messages are implemented via
 @racket[subprocess-kill], so they can affect a process group instead
 of a single process.}
- 
 
-@defproc*[([(process* [command path-string?] [arg (or/c path? string? bytes?)] ...) list?]
+
-           [(process* [command path-string?] [exact 'exact] [arg string?]) list?])]{
+@defproc*[([(process* [command path-string?]
+                      [arg (or/c path? string-no-nuls? bytes-no-nuls?)] ...)
+            list?]
+           [(process* [command path-string?] [exact 'exact] [arg string?])
+            list?])]{
 
 Like @racket[process], except that @racket[command] is a filename that
 is executed directly like @racket[system*], and the @racket[arg]s are the arguments. On
@@ -452,7 +463,7 @@ replaced with @racket['exact].}
 @defproc[(process/ports [out (or/c #f output-port?)]
                         [in (or/c #f input-port?)]
                         [error-out (or/c #f output-port? 'stdout)]
-                        [command string?])
+                        [command (or/c path? string-no-nuls? bytes-no-nuls?)])
          list?]{
 
 Like @racket[process], except that @racket[out] is used for the
@@ -469,7 +480,8 @@ returned list is @racket[#f].}
                             [in (or/c #f input-port?)]
                             [error-out (or/c #f output-port? 'stdout)]
                             [command path-string?]
-                            [arg (or/c path? string? bytes?)] ...)
+                            [arg (or/c path? string-no-nuls? bytes-no-nuls?)]
+                            ...)
             list?]
            [(process*/ports [out (or/c #f output-port?)]
                             [in (or/c #f input-port?)]
@@ -489,10 +501,10 @@ Like @racket[process*], but with the port handling of
 @;note-lib[racket/system]
 
 The contracts of @racket[system] and related functions may signal a
-contract error with references to the following functions. 
+contract error with references to the following functions.
 
 @defproc[(string-no-nuls? [x any/c]) boolean?]{
 Ensures that @racket[x] is a string and does not contain @racket["\0"].}
 
 @defproc[(bytes-no-nuls? [x any/c]) boolean?]{
-Ensures that @racket[x] is a byte-string and does not contain @racket["\0"].}
+Ensures that @racket[x] is a byte-string and does not contain @racket[#"\0"].}

src/racket/src/port.c

@@ -8937,12 +8937,9 @@ static Scheme_Object *subprocess(int c, Scheme_Object *args[])
       if (((!SCHEME_CHAR_STRINGP(args[i]) && !SCHEME_BYTE_STRINGP(args[i]))
            || scheme_any_string_has_null(args[i]))
           && !SCHEME_PATHP(args[i]))
-	scheme_wrong_contract(name, 
+	scheme_wrong_contract(name,
-                              ("(or/c path?\n"
+                              "(or/c path? string-no-nuls? bytes-no-nuls?)",
-                               "      (and/c string? (lambda (s) (not (memv #\\nul (string->list s)))))\n"
-                               "      (and/c bytes? (lambda (bs) (not (memv 0 (bytes->list bs))))))"),
                               i, c, args);
-        
       {
 	Scheme_Object *bs;
         bs = args[i];

src/racket/src/schpriv.h

@@ -3378,7 +3378,7 @@ const char *scheme_hostname_error(int err);
 
 int scheme_byte_string_has_null(Scheme_Object *o);
 int scheme_any_string_has_null(Scheme_Object *o);
-#define CHAR_STRING_W_NO_NULLS "(and/c string? (lambda (s) (not (memv #\\nul (string->list s)))))"
+#define CHAR_STRING_W_NO_NULLS "string-no-nuls?"
 
 Scheme_Object *scheme_do_exit(int argc, Scheme_Object *argv[]);