/*  $NetBSD: echo.c,v 1.12 2005/02/06 04:43:43 perry Exp $  */

/*-
 * Copyright (c) 1991, 1993
 *  The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 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. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *  @(#)echo.c  8.1 (Berkeley) 5/31/93
 */

/*
 * Echo command.
 *
 * echo is steeped in tradition - several of them!
 * netbsd has supported 'echo [-n | -e] args' in spite of -e not being
 * documented anywhere.
 * Posix requires that -n be supported, output from strings containing
 * \ is implementation defined
 * The Single Unix Spec requires that \ escapes be treated as if -e
 * were set, but that -n not be treated as an option.
 * (ksh supports 'echo [-eEn] args', but not -- so that it is actually
 * impossible to actually output '-n')
 *
 * It is suggested that 'printf "%b" "string"' be used to get \ sequences
 * expanded.  printf is now a builtin of netbsd's sh and csh.
 */

/*
 *  $Id$
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>

#include <rtems.h>
#include <rtems/shell.h>
#include "internal.h"



int rtems_shell_main_echo(
  int   argc,
  char *argv[]
)
{
  char **ap;
  char *p;
  char c;
  int count;
  int nflag = 0;
  int eflag = 0;

  ap = argv;
  if (argc)
    ap++;

  if ((p = *ap) != NULL) {
    if (!strcmp(p, "-n")) {
      nflag = 1;
      ap++;
    } else if (!strcmp(p, "-e")) {
      eflag = 1;
      ap++;
    }
  }

  while ((p = *ap++) != NULL) {
    while ((c = *p++) != '\0') {
      if (c == '\\' && eflag) {
        switch (*p++) {
        case 'a':  c = '\a';  break;  /* bell */
        case 'b':  c = '\b';  break;
        case 'c':  return 0;    /* exit */
        case 'e':  c =  033;  break;  /* escape */
        case 'f':  c = '\f';  break;
        case 'n':  c = '\n';  break;
        case 'r':  c = '\r';  break;
        case 't':  c = '\t';  break;
        case 'v':  c = '\v';  break;
        case '\\':  break;    /* c = '\\' */
        case '0':
          c = 0;
          count = 3;
          while (--count >= 0 && (unsigned)(*p - '0') < 8)
            c = (c << 3) + (*p++ - '0');
          break;
        default:
          /* Output the '/' and char following */
          p--;
          break;
        }
      }
      putchar(c);
    }
    if (*ap)
      putchar(' ');
  }
  if (! nflag)
    putchar('\n');
  return 0;
}

rtems_shell_cmd_t rtems_shell_ECHO_Command = {
  "echo",                        /* name */
  "echo [args]",                 /* usage */
  "misc",                        /* topic */
  rtems_shell_main_echo,         /* command */
  NULL,                          /* alias */
  NULL                           /* next */
};