xbfmg.c

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libgen.h>
#include <unistd.h>
#include <sys/stat.h>

#include "bufrlib.h"

#ifdef UNDERSCORE
#define prtusage prtusage_
#endif

void prtusage( char * );

#define MXFLEN 125

void prtusage( char *prgnam ) {
    printf( "\nUSAGE: %s [-v] [-h] [-g] bufrfile\n\n", prgnam );
    printf( "WHERE:\n" );
    printf( "    -v        prints program version information and exits\n" );
    printf( "    -h        prints program help and usage information and exits\n" );
    printf( "    -g        preserves within each output file any GTS bulletin header and\n" );
    printf( "              control characters associated with the corresponding BUFR message\n" );
    printf( "              from the input file\n" );
    printf( "   bufrfile   [path/]name of input file containing one or more BUFR messages\n" );
    printf( "              to be extracted into separate output files within the current\n" );
    printf( "              working directory\n\n" );
    printf( "The output will be stored within the current working directory using the\n" );
    printf( "following filenames:\n\n" );
    printf( "    (basename).xbfmg.out.000001\n" );
    printf( "    (basename).xbfmg.out.000002\n" );
    printf( "    (basename).xbfmg.out.000003\n" );
    printf( "      .\n" );
    printf( "      .\n" );
    printf( "    (basename).xbfmg.out.(last#)\n\n" );
    printf( "where:\n\n" );
    printf( "    (basename) = basename of bufrfile\n" );
    printf( "    (last#) = total number of BUFR messages in bufrfile\n\n" );
}

int main( int argc, char *argv[] ) {

    struct stat fileinfo;

    char *pc, *pmsg, *psb;

    int save_GTSbull = 0;

    char outfile[MXFLEN];
    char outfile_temp[MXFLEN];
    char wkstr[MXFLEN];

    char *bvstr;

    int ch;

    FILE *fp;

    f77int msglen, wkint;
    f77int c24 = 24, c1 = 1;

    unsigned long i, filesize, noutfile;

    unsigned short ii;

    /*
    **  Get the valid options from the command line:
    */
        while ( ( ch = getopt ( argc, argv, "vgh" ) ) != EOF ) {
            switch ( ch ) {
        case 'v':
            bvstr = ( char * ) calloc( 9, sizeof(char) );  /* allocate bvstr and initialize to all nulls */
            bvers( bvstr, sizeof(bvstr) );
            printf( "This is xbfmg v3.2.0, built with BUFRLIB v%s\n", bvstr );
            return 0;
        case 'g':
            save_GTSbull = 1;
            break;
        case 'h':
                    printf( "\nPROGRAM %s\n", argv[0] );
                    printf( "\nABSTRACT: This program reads an input file containing one or more\n" );
                    printf( "  BUFR messages as given by the first argument.  It then extracts each\n" );
                    printf( "  each individual BUFR message into its own separate output file within\n" );
                    printf( "  the current working directory.\n" );
                    prtusage( argv[0] );
                    return 0;
                    break;
            }
        }

    /*
    **  There should be one remaining command line argument specifying the input file.
    */
    if ( (optind+1) != argc ) {
        printf( "\nERROR: You must specify an input BUFR file of BUFR messages!\n" );
            prtusage( argv[0] );
        return -1;
    }

    /*
    **  Get the filesize of the input file.
    */
    if ( stat( argv[optind], &fileinfo ) != 0 ) {
        printf( "\nERROR: Could not stat the file %s!\n", argv[optind] );
        return -1;
    }
    filesize = fileinfo.st_size;

    /*
    **  Dynamically allocate memory in order to read in the input file.
    */
    if ( ( pc = malloc( filesize + 1 ) ) == NULL ) {
        printf( "\nERROR: Could not allocate memory for file %s!\n", argv[optind] );
        return -1;
    }

    /*
    **  Read the input file into memory.
    */
    if ( ( fp = fopen( argv[optind], "rb" ) ) == NULL ) {
        printf( "\nERROR: Could not open input file %s!\n", argv[optind] );
        return -1;
    }
    for ( i = 0; i < filesize; i++ ) {
        pc[i] = (char) fgetc( fp );
    } 
    pc[i] = '\0';
    fclose( fp );

    /*
    **  Create an output file name template.
    */
    strcpy( wkstr, argv[optind] );
    strcpy( outfile_temp, basename( wkstr ) );
    strcat( outfile_temp, ".xbfmg.out" );

    /*
    **  Call wrdlen function to initialize BUFRLIB and determine machine endianness.
    */
    wrdlen( );

    /*
    **  Locate each BUFR message within the input file and write each one to a separate output file.
    **
    **  Note that we can't use the intrinsic C strstr function to locate the "BUFR" and "7777"
    **  strings within the file, because the file could contain embedded NULL characters.
    */
    noutfile = 0;
    pmsg = psb = pc;
    while ( 1 ) {
        while (  ( ( pmsg - pc + 4 ) < filesize )  &&
            ( ( *(pmsg)     != 'B' )  ||
              ( *(pmsg + 1) != 'U' )  || 
              ( *(pmsg + 2) != 'F' )  ||
              ( *(pmsg + 3) != 'R' ) )  )  {
        if ( *pmsg == '\x01' ) psb = pmsg;
        pmsg++;
        }
        if  ( ( pmsg - pc + 4 ) >= filesize )  {
        free( pc );
        return 0;
        }

        /*
        **  Open a new output file for this message.
        */
        sprintf( outfile, "%s.%06lu", outfile_temp, ++noutfile );
        if ( ( fp = fopen( outfile, "wb" ) ) == NULL ) {
        printf( "\nERROR: Could not open output file %s!\n", outfile );
        return -1;
        }

        /*
        **  If requested, write the preceding GTS bulletin information to the output file.
        */
        if ( save_GTSbull ) {
        while ( psb < pmsg ) {
            fputc( *psb++, fp );
        }
        }

        /*
        **  Read the BUFR message length from Section 0.
        */
        memcpy( &wkint, ( pmsg + 4 ), 3 );
        msglen = iupb( &wkint, &c1, &c24 );

        /*
        **  Write the BUFR message to the output file.
        */
        if  ( ( pmsg + msglen - pc - 1 ) <= filesize ) {
        for ( i = 1; i <= msglen; i++ ) {
            fputc( *pmsg++, fp );
        }
        }

        /*
        **  Make sure that the "7777" indicator is in the expected place.
        */
        if ( ( *(pmsg - 4) != '7' ) || ( *(pmsg - 3) != '7' ) || 
             ( *(pmsg - 2) != '7' ) || ( *(pmsg - 1) != '7' ) )  {
            printf( "\nERROR: Could not find 7777 indicator in output file %s!\n",
            outfile );
        }

        /*
        **  If requested, append GTS bulletin tail markers to the output file.
        */
        if ( save_GTSbull ) {
        fputc( '\x0d', fp );
        fputc( '\x0d', fp );
        fputc( '\x0a', fp );
        fputc( '\x03', fp );
        }

        fclose( fp );
    }   
}