GDP

/* vim: set ai sw=8 sts=8 ts=8 :*/

/***********************************************************************

**  ----- BEGIN LICENSE BLOCK -----

**        LIBEP: Enhanced Portability Library (Reduced Edition)

**

**        Copyright (c) 2008-2019, Eric P. Allman.  All rights reserved.

**        Copyright (c) 2015-2019, Regents of the University of California.

**        All rights reserved.

**

**        Permission is hereby granted, without written agreement and without

**        license or royalty fees, to use, copy, modify, and distribute this

**        software and its documentation for any purpose, provided that the above

**        copyright notice and the following two paragraphs appear in all copies

**        of this software.

**

**        IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,

**        SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST

**        PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION,

**        EVEN IF REGENTS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

**

**        REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT

**        LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS

**        FOR A PARTICULAR PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION,

**        IF ANY, PROVIDED HEREUNDER IS PROVIDED "AS IS". REGENTS HAS NO

**        OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,

**        OR MODIFICATIONS.

**  ----- END LICENSE BLOCK -----

***********************************************************************/

/*

**  Open up a stream that has styling (e.g., colors or fonts)

**

**        This is a wrapper around funopen (on BSD and MacOS) or

**        fopencookie (on Linux).  These two routimes do substantially

**        the same thing.

*/

#if __FreeBSD__ || __APPLE__

#   define IORESULT_T        int

#   define IOBLOCK_T        int

#elif __linux__

#   define IORESULT_T        ssize_t

#   define IOBLOCK_T        size_t

#   define _GNU_SOURCE        1        // required to get fopencookie

#else

#   error Cannot determine use of funopen vs fopencookie

#endif

#include <ep.h>

#include <string.h>

#include <stdio.h>

#include <sys/errno.h>

struct styleinfo

{

        FILE        *underlying;        // underlying file

        char        *so;                // "shift out" string

        char        *si;                // "shift in" string

};

static IORESULT_T

styled_write(void *cookie, const char *buf, IOBLOCK_T size)

{

        struct styleinfo *sinf = (struct styleinfo *) cookie;

        IORESULT_T result = 0;

        flockfile(sinf->underlying);

        while (size > 0)

        {

                const char *p;

                IOBLOCK_T tlen;

                tlen = size;

                p = memchr(buf, '\n', tlen);

                if (p != NULL)

                        tlen = p - buf;

                if (tlen > 0)

                {

                        IORESULT_T tres;

                        if (sinf->so != NULL)

                                fputs(sinf->so, sinf->underlying);

                        tres = fwrite(buf, 1, tlen, sinf->underlying);

                        if (sinf->si != NULL)

                                fputs(sinf->si, sinf->underlying);

                        buf += tlen;

                        size -= tlen;

                        if (tres > 0)

                                result += tres;

                }

                if (size > 0 && *buf == '\n')

                {

                        fputc(*buf++, sinf->underlying);

                        result++;

                        size--;

                }

        }

        funlockfile(sinf->underlying);

        fflush(sinf->underlying);

        return result;

}

static int

styled_close(void *cookie)

{

        struct styleinfo *sinf = (struct styleinfo *) cookie;

        if (sinf->so != NULL)

                ep_mem_free(sinf->so);

        if (sinf->si != NULL)

                ep_mem_free(sinf->si);

        ep_mem_free(cookie);

        return 0;

}

FILE *

ep_fopen_styled(FILE *underlying,

                const char *so,

                const char *si)

{

        FILE *fp;

        struct styleinfo *sinf = (struct styleinfo *) ep_mem_zalloc(sizeof *sinf);

        if (sinf == NULL)

                return NULL;

        sinf->underlying = underlying;

        if (so != NULL)

                sinf->so = strdup(so);

        if (si != NULL)

                sinf->si = strdup(si);

#if __FreeBSD__ || __APPLE__

        {

                // BSD/MacOS

                fp = funopen(sinf, NULL, &styled_write, NULL, &styled_close);

        }

#elif __linux__

        {

                // Linux

                cookie_io_functions_t iof =

                {

                        NULL,

                        &styled_write,

                        NULL,

                        &styled_close

                };

                fp = fopencookie(sinf, "w", iof);

        }

#endif

        setlinebuf(fp);

        return fp;

}