cp: revert a recent buggy change, and add a comment why it's wrong

[oweals/busybox.git] / findutils / xargs.c

diff --git a/findutils/xargs.c b/findutils/xargs.c
index ee16ea675da26cd5f0c582735c52f45bc0793cfe..76d1d5489037a63aae2e7cc7c387ccca80287627 100644 (file)
--- a/findutils/xargs.c
+++ b/findutils/xargs.c
@@ -233,7 +233,7 @@ static xlist_t *process_stdin(xlist_t *list_arg,
                }
                if (s == NULL)
                        s = p = buf;
-               if ((p - buf) >= mc)
+               if ((size_t)(p - buf) >= mc)
                        bb_error_msg_and_die("argument line too long");
                *p++ = (c == EOF ? '\0' : c);
                if (c == EOF) { /* word's delimiter or EOF detected */
@@ -277,7 +277,7 @@ static int xargs_ask_confirmation(void)
        FILE *tty_stream;
        int c, savec;
 
-       tty_stream = xfopen(CURRENT_TTY, "r");
+       tty_stream = xfopen_for_read(CURRENT_TTY);
        fputs(" ?...", stderr);
        fflush(stderr);
        c = savec = getc(tty_stream);
@@ -292,7 +292,7 @@ static int xargs_ask_confirmation(void)
 
 #if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
 static xlist_t *process0_stdin(xlist_t *list_arg,
-               const char *eof_str ATTRIBUTE_UNUSED, size_t mc, char *buf)
+               const char *eof_str UNUSED_PARAM, size_t mc, char *buf)
 {
        int c;                  /* current char */
        char *s = NULL;         /* start word */
@@ -355,23 +355,25 @@ enum {
        OPTBIT_UPTO_NUMBER,
        OPTBIT_UPTO_SIZE,
        OPTBIT_EOF_STRING,
-       USE_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,)
-       USE_FEATURE_XARGS_SUPPORT_TERMOPT(     OPTBIT_TERMINATE  ,)
-       USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(   OPTBIT_ZEROTERM   ,)
-
-       OPT_VERBOSE     = 1<<OPTBIT_VERBOSE    ,
-       OPT_NO_EMPTY    = 1<<OPTBIT_NO_EMPTY   ,
-       OPT_UPTO_NUMBER = 1<<OPTBIT_UPTO_NUMBER,
-       OPT_UPTO_SIZE   = 1<<OPTBIT_UPTO_SIZE  ,
-       OPT_EOF_STRING  = 1<<OPTBIT_EOF_STRING ,
-       OPT_INTERACTIVE = USE_FEATURE_XARGS_SUPPORT_CONFIRMATION((1<<OPTBIT_INTERACTIVE)) + 0,
-       OPT_TERMINATE   = USE_FEATURE_XARGS_SUPPORT_TERMOPT(     (1<<OPTBIT_TERMINATE  )) + 0,
-       OPT_ZEROTERM    = USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(   (1<<OPTBIT_ZEROTERM   )) + 0,
+       OPTBIT_EOF_STRING1,
+       IF_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,)
+       IF_FEATURE_XARGS_SUPPORT_TERMOPT(     OPTBIT_TERMINATE  ,)
+       IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(   OPTBIT_ZEROTERM   ,)
+
+       OPT_VERBOSE     = 1 << OPTBIT_VERBOSE    ,
+       OPT_NO_EMPTY    = 1 << OPTBIT_NO_EMPTY   ,
+       OPT_UPTO_NUMBER = 1 << OPTBIT_UPTO_NUMBER,
+       OPT_UPTO_SIZE   = 1 << OPTBIT_UPTO_SIZE  ,
+       OPT_EOF_STRING  = 1 << OPTBIT_EOF_STRING , /* GNU: -e[<param>] */
+       OPT_EOF_STRING1 = 1 << OPTBIT_EOF_STRING1, /* SUS: -E<param> */
+       OPT_INTERACTIVE = IF_FEATURE_XARGS_SUPPORT_CONFIRMATION((1 << OPTBIT_INTERACTIVE)) + 0,
+       OPT_TERMINATE   = IF_FEATURE_XARGS_SUPPORT_TERMOPT(     (1 << OPTBIT_TERMINATE  )) + 0,
+       OPT_ZEROTERM    = IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(   (1 << OPTBIT_ZEROTERM   )) + 0,
 };
-#define OPTION_STR "+trn:s:e::" \
-       USE_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \
-       USE_FEATURE_XARGS_SUPPORT_TERMOPT(     "x") \
-       USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(   "0")
+#define OPTION_STR "+trn:s:e::E:" \
+       IF_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \
+       IF_FEATURE_XARGS_SUPPORT_TERMOPT(     "x") \
+       IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(   "0")
 
 int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int xargs_main(int argc, char **argv)
@@ -385,7 +387,7 @@ int xargs_main(int argc, char **argv)
        int n_max_arg;
        size_t n_chars = 0;
        long orig_arg_max;
-       const char *eof_str = "_";
+       const char *eof_str = NULL;
        unsigned opt;
        size_t n_max_chars;
 #if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
@@ -394,10 +396,16 @@ int xargs_main(int argc, char **argv)
 #define read_args process_stdin
 #endif
 
-       opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &eof_str);
+       opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &eof_str, &eof_str);
+
+       /* -E ""? You may wonder why not just omit -E?
+        * This is used for portability:
+        * old xargs was using "_" as default for -E / -e */
+       if ((opt & OPT_EOF_STRING1) && eof_str[0] == '\0')
+               eof_str = NULL;
 
        if (opt & OPT_ZEROTERM)
-               USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);
+               IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);
 
        argv += optind;
        argc -= optind;
@@ -502,7 +510,7 @@ int xargs_main(int argc, char **argv)
                if (child_error > 0 && child_error != 123) {
                        break;
                }
-       }
+       } /* while */
        if (ENABLE_FEATURE_CLEAN_UP)
                free(max_chars);
        return child_error;
@@ -517,7 +525,7 @@ void bb_show_usage(void)
 {
        fprintf(stderr, "Usage: %s [-p] [-r] [-t] -[x] [-n max_arg] [-s max_chars]\n",
                applet_name);
-       exit(1);
+       exit(EXIT_FAILURE);
 }
 
 int main(int argc, char **argv)