shell_cmds-179.tar.gz

[apple/shell_cmds.git] / echo / echo.c

diff --git a/echo/echo.c b/echo/echo.c
index bbb05396f650890dc74b3227bdba881c82d4e013..629e22f1e09d8fe15ae8d1bc7f45202f78f79c18 100644 (file)
--- a/echo/echo.c
+++ b/echo/echo.c
@@ -1,4 +1,4 @@
-/*
+/*-
  * Copyright (c) 1989, 1993
  *     The Regents of the University of California.  All rights reserved.
  *
@@ -10,10 +10,6 @@
  * 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.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *     This product includes software developed by the University of
- *     California, Berkeley and its contributors.
  * 4. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
@@ -31,6 +27,7 @@
  * SUCH DAMAGE.
  */
 
+#if 0
 #ifndef lint
 static char const copyright[] =
 "@(#) Copyright (c) 1989, 1993\n\
@@ -38,32 +35,66 @@ static char const copyright[] =
 #endif /* not lint */
 
 #ifndef lint
-#if 0
 static char sccsid[] = "@(#)echo.c     8.1 (Berkeley) 5/31/93";
-#endif
 #endif /* not lint */
+#endif
 #include <sys/cdefs.h>
-__RCSID("$FreeBSD: src/bin/echo/echo.c,v 1.13 2002/06/30 05:13:53 obrien Exp $");
+__FBSDID("$FreeBSD: src/bin/echo/echo.c,v 1.18 2005/01/10 08:39:22 imp Exp $");
 
-#include <stdio.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+
+#include <assert.h>
+#include <errno.h>
+#include <limits.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 
-/* ARGSUSED */
+/*
+ * Report an error and exit.
+ * Use it instead of err(3) to avoid linking-in stdio.
+ */
+static void
+errexit(const char *prog, const char *reason)
+{
+       char *errstr = strerror(errno);
+       write(STDERR_FILENO, prog, strlen(prog));
+       write(STDERR_FILENO, ": ", 2);
+       write(STDERR_FILENO, reason, strlen(reason));
+       write(STDERR_FILENO, ": ", 2);
+       write(STDERR_FILENO, errstr, strlen(errstr));
+       write(STDERR_FILENO, "\n", 1);
+       exit(1);
+}
+       
 int
 main(int argc, char *argv[])
 {
        int nflag;      /* if not set, output a trailing newline. */
+       int veclen;     /* number of writev arguments. */
+       struct iovec *iov, *vp; /* Elements to write, current element. */
+       char space[] = " ";
+       char newline[] = "\n";
+       char *progname = argv[0];
 
        /* This utility may NOT do getopt(3) option parsing. */
        if (*++argv && !strcmp(*argv, "-n")) {
                ++argv;
+               --argc;
                nflag = 1;
-       }
-       else
+       } else
                nflag = 0;
 
+       veclen = (argc >= 2) ? (argc - 2) * 2 + 1 : 0;
+
+       if ((vp = iov = malloc((veclen + 1) * sizeof(struct iovec))) == NULL)
+               errexit(progname, "malloc");
+
        while (argv[0] != NULL) {
+               size_t len;
+               
+               len = strlen(argv[0]);
 
                /*
                 * If the next argument is NULL then this is this
@@ -71,23 +102,36 @@ main(int argc, char *argv[])
                 * for a trailing \c.
                 */
                if (argv[1] == NULL) {
-                       size_t len;
-                       
-                       len = strlen(argv[0]);
                        /* is there room for a '\c' and is there one? */
                        if (len >= 2 &&
                            argv[0][len - 2] == '\\' &&
                            argv[0][len - 1] == 'c') {
                                /* chop it and set the no-newline flag. */
-                               argv[0][len - 2] = '\0';
+                               len -= 2;
                                nflag = 1;
                        }
                }
-               (void)printf("%s", argv[0]);
-               if (*++argv)
-                       putchar(' ');
+               vp->iov_base = *argv;
+               vp++->iov_len = len;
+               if (*++argv) {
+                       vp->iov_base = space;
+                       vp++->iov_len = 1;
+               }
+       }
+       if (!nflag) {
+               veclen++;
+               vp->iov_base = newline;
+               vp++->iov_len = 1;
+       }
+       /* assert(veclen == (vp - iov)); */
+       while (veclen) {
+               int nwrite;
+
+               nwrite = (veclen > IOV_MAX) ? IOV_MAX : veclen;
+               if (writev(STDOUT_FILENO, iov, nwrite) == -1)
+                       errexit(progname, "write");
+               iov += nwrite;
+               veclen -= nwrite;
        }
-       if (!nflag)
-               putchar('\n');
        return 0;
 }