usr/src/bin/sh/bltin/echo.c

/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * %sccs.include.redist.c%
 *
 *      @(#)echo.c      5.1 (Berkeley) %G%
 */

/*
 * Echo command.
 */

#define main echocmd

#include "bltin.h"

#define EOF (-1)

main(argc, argv)
        char **argv;
{
        register char *p;
        register char c;
        int count;
        int nflag = 0;
        int eflag = 0;
        extern char *optarg;
        extern int optind, opterr;
        int ch;

        opterr = 0;
        while ((ch = getopt(argc, argv, "ne")) != EOF)
                switch((char)ch) {
                case 'n':
                        nflag++;
                        break;
                case 'e':
                        eflag++;
                        break;
                case '?':
                default:
                        error("usage: %s [-ne] [arg]...", *argv);
                        return 0;
                }
        argc -= optind;
        argv += optind;

        if (!eflag) {
                while (p = *argv++) {
                        while (*p) {
                                putchar(*p);
                                p++;
                        }
                        if (*argv) putchar(' ');
                }
        } else {
                while (p = *argv++) {
                        while (c = *p++) {
                                if (c == '\\') {
                                        switch (*p++) {
                                        case 'b':  c = '\b';  break;
                                        case 'c':  return 0;    /* exit */
                                        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':       /* should be [0-7] */
                                              c = 0;
                                              count = 3;
                                              while (--count >= 0 && (unsigned)(*p - '0') < 8)
                                                    c = (c << 3) + (*p++ - '0');
                                              break;
                                        default:
                                                p--;
                                              break;
                                        }
                                }
                                putchar(c);
                        }
                        if (*argv) putchar(' ');
                }
        }
        if (!nflag)
                putchar('\n');
        return 0;
}

#ifndef SHELL
void
error(f, a)
{
        _doprnt(f, &a, stderr);
}
#endif