libcmd/common/rev.c

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1992-2010 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                                                                      *
***********************************************************************/
#pragma prototyped
/*
 * rev [-l] [file ...]
 *
 * reverse the characters or lines of one or more files
 *
 *   David Korn
 *   AT&T Laboratories
 *   dgk@research.att.com
 *
 */

static const char usage[] =
"[-?\n@(#)$Id: rev (AT&T Research) 2007-11-29 $\n]"
USAGE_LICENSE
"[+NAME?rev - reverse the characters or lines of one or more files]"
"[+DESCRIPTION?\brev\b copies one or more files to standard output "
    "reversing the order of characters on every line of the file "
    "or reversing the order of lines of the file if \b-l\b is specified.]"
"[+?If no \afile\a is given, or if the \afile\a is \b-\b, \brev\b "
        "copies from standard input starting at the current offset.]"
"[l:line?Reverse the lines of the file.]"

"\n"
"\n[file ...]\n"
"\n"
"[+EXIT STATUS?]{"
        "[+0?All files copied successfully.]"
        "[+>0?One or more files did not copy.]"
"}"
"[+SEE ALSO?\bcat\b(1), \btail\b(1)]"
;

#include    <cmd.h>
#include    <rev.h>

/*
 * reverse the characters within a line
 */
static int rev_char(Sfio_t *in, Sfio_t *out)
{
    register int c;
    register char *ep, *bp, *cp;
    register wchar_t *wp, *xp;
    register size_t n;
    register size_t w;
    if (mbwide())
    {
        wp = 0;
        w = 0;
        while(cp = bp = sfgetr(in,'\n',0))
        {
            ep = bp + (n=sfvalue(in)) - 1;
            if (n > w)
            {
                w = roundof(n + 1, 1024);
                if (!(wp = newof(wp, wchar_t, w, 0)))
                {
                    error(ERROR_SYSTEM|2, "out of space");
                    return 0;
                }
            }
            xp = wp;
            while (cp < ep)
                *xp++ = mbchar(cp);
            cp = bp;
            while (xp > wp)
                cp += mbconv(cp, *--xp);
            *cp++ = '\n';
            if (sfwrite(out, bp, cp - bp) < 0)
                return -1;
        }
        if (wp)
            free(wp);
    }
    else
        while(cp = bp = sfgetr(in,'\n',0))
        {
            ep = bp + (n=sfvalue(in)) -1;
            while(ep > bp)
            {
                c = *--ep;
                *ep = *bp;
                *bp++ = c;
            }
            if(sfwrite(out,cp,n)<0)
                return(-1);
        }
    return(0);
}

int
b_rev(int argc, register char** argv, void* context)
{
    register Sfio_t *fp;
    register char *cp;
    register int n, line=0;
    NOT_USED(argc);

    cmdinit(argc, argv, context, ERROR_CATALOG, 0);
    while (n = optget(argv, usage)) switch (n)
    {
        case 'l':
        line=1;
        break;
        case ':':
        error(2, "%s", opt_info.arg);
        break;
        case '?':
        error(ERROR_usage(2), "%s", opt_info.arg);
        break;
    }
    argv += opt_info.index;
    if(error_info.errors)
        error(ERROR_usage(2),"%s",optusage((char*)0));
    n=0;
    if(cp = *argv)
        argv++;
    do
    {
        if(!cp || streq(cp,"-"))
            fp = sfstdin;
        else if(!(fp = sfopen((Sfio_t*)0,cp,"r")))
        {
            error(ERROR_system(0),"%s: cannot open",cp);
            n=1;
            continue;
        }
        if(line)
            line = rev_line(fp,sfstdout,sftell(fp));
        else
            line = rev_char(fp,sfstdout);
        if(fp!=sfstdin)
            sfclose(fp);
        if(line < 0)
            error(ERROR_system(1),"write failed");
    }
    while(cp= *argv++);
    return(n);
}