dev_file_encod_readline_wstr.c

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/* UTF-encoded file device LINE INPUT for wstrings */

#include "fb.h"

int fb_DevFileReadLineEncodWstr( FB_FILE *handle, FB_WCHAR *dst, ssize_t max_chars )
{
        int res;

        FB_LOCK();

        FILE* fp = (FILE *)handle->opaque;
        if( fp == stdout || fp == stderr )
                fp = stdin;

        if( fp == NULL ) {
                FB_UNLOCK();
                return fb_ErrorSetNum( FB_RTERROR_ILLEGALFUNCTIONCALL );
        }

        /* Clear string first, we're only using += concat assign below... */
        dst[0] = _LC('\0');

        /* Read one byte at a time until CR and/or LF is found.
           The fb_FileGetDataEx() will handle the decoding. The length to read
           is specified in wchars, not bytes, because we're passing TRUE for
           is_unicode. */
        while( TRUE ) {
                FB_WCHAR c[2];
                size_t len;

                res = fb_FileGetDataEx( handle, 0, c, 1, &len, FALSE, TRUE );
                if( (res != FB_RTERROR_OK) || (len == 0) )
                        break;

                /* CR? Check for following LF too, and skip it if it's there */
                if( c[0] == _LC('\r') ) {
                        res = fb_FileGetDataEx( handle, 0, c, 1, &len, FALSE, TRUE );
                        if( (res != FB_RTERROR_OK) || (len == 0) )
                                break;

                        /* No LF? Ok then, don't skip it yet */
                        if( c[0] != _LC('\n') )
                                fb_FilePutBackEx( handle, c, 1 );

                        break;
                }

                /* LF? */
                if( c[0] == _LC('\n') ) {
                        break;
                }

                /* Any other char? Append to string, and continue... */
                c[1] = _LC('\0');
                fb_WstrConcatAssign( dst, max_chars, c );
        }

        FB_UNLOCK();

        return res;
}