sh/bltin/echo.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1991, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Kenneth Almquist.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)echo.c      8.2 (Berkeley) 5/4/95
  35  */
  36
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD: head/bin/sh/bltin/echo.c 326025 2017-11-20 19:49:47Z pfg $");
  39
  40 /*
  41  * Echo command.
  42  */
  43
  44 #define main echocmd
  45
  46 #include "bltin.h"
  47
  48 /* #define eflag 1 */
  49
  50 int
  51 main(int argc, char *argv[])
  52 {
  53         char **ap;
  54         char *p;
  55         char c;
  56         int count;
  57         int nflag = 0;
  58 #ifndef eflag
  59         int eflag = 0;
  60 #endif
  61
  62         ap = argv;
  63         if (argc)
  64                 ap++;
  65         if ((p = *ap) != NULL) {
  66                 if (equal(p, "-n")) {
  67                         nflag++;
  68                         ap++;
  69                 } else if (equal(p, "-e")) {
  70 #ifndef eflag
  71                         eflag++;
  72 #endif
  73                         ap++;
  74                 }
  75         }
  76         while ((p = *ap++) != NULL) {
  77                 while ((c = *p++) != '\0') {
  78                         if (c == '\\' && eflag) {
  79                                 switch (*p++) {
  80                                 case 'a':  c = '\a';  break;
  81                                 case 'b':  c = '\b';  break;
  82                                 case 'c':  return 0;            /* exit */
  83                                 case 'e':  c = '\033';  break;
  84                                 case 'f':  c = '\f';  break;
  85                                 case 'n':  c = '\n';  break;
  86                                 case 'r':  c = '\r';  break;
  87                                 case 't':  c = '\t';  break;
  88                                 case 'v':  c = '\v';  break;
  89                                 case '\\':  break;              /* c = '\\' */
  90                                 case '0':
  91                                         c = 0;
  92                                         count = 3;
  93                                         while (--count >= 0 && (unsigned)(*p - '0') < 8)
  94                                                 c = (c << 3) + (*p++ - '0');
  95                                         break;
  96                                 default:
  97                                         p--;
  98                                         break;
  99                                 }
 100                         }
 101                         putchar(c);
 102                 }
 103                 if (*ap)
 104                         putchar(' ');
 105         }
 106         if (! nflag)
 107                 putchar('\n');
 108         return 0;
 109 }