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 "bufr_interface.h"
 
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, *outfile_temp;
 
    char bvstr[VERS_STR_LEN+1];
 
    int ch;
 
    FILE *fp;
 
    int msglen, wkint[2];
 
    unsigned long i, filesize, noutfile;
 
    /*
    **  Get the valid options from the command line:
    */
    while ( ( ch = getopt ( argc, argv, "vgh" ) ) != EOF ) {
        switch ( ch ) {
            case 'v':
                bvers_f( bvstr, VERS_STR_LEN+1 );
                printf( "This is the xbfmg utility, built with NCEPLIBS-bufr 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] );
        free(pc);
        return -1;
    }
    for ( i = 0; i < filesize; i++ ) {
        pc[i] = (char) fgetc( fp );
    }
    pc[i] = '\0';
    fclose( fp );
 
    /*
    **  Create an output file name template.
    */
    if ( ( outfile_temp = malloc( strlen( argv[optind] ) + 26 ) ) == NULL ) {
        // allow for up to 25 extra chars so that we can strcat an additional filename qualifier below
        printf( "\nERROR: Could not allocate memory for output file name template!\n" );
        return -1;
    }
    strcpy( outfile_temp, basename( argv[optind] ) );
    strcat( outfile_temp, ".xbfmg.out" );
    if ( ( outfile = malloc( strlen( outfile_temp ) + 26 ) ) == NULL ) {
        // allow for up to 25 extra chars so that we can sprintf an additional filename qualifier below
        printf( "\nERROR: Could not allocate memory for output file names!\n" );
        return -1;
    }
 
    /*
    **  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 );
            free( outfile_temp );
            free( outfile );
            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, 8 );
        msglen = iupbs01_f( wkint, "LENM" );
 
        /*
        **  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 );
    }
}