$ cat mysrc/p2csv.c
#include <stdio.h>
main( int argc, char **argv )
{
        char    usage[] =
"\n"
"Usage: p2csv [ -s <sep> ]\n"
"\n"
"Changes the file column delimited by <sep> (pipe '|' default) from standard\n"
"input to a Comma Separated Values (CSV) formatted file on standard output.\n"
"\n" ;
        int     sep = '|' ;     /* input column separator character */
        int     c ;             /* character read */
        int     cl = 0 ;        /* found chars not leading/trailing space */
        int     fs = 0 ;        /* possibly embedded spaces found */
        int     fp = 0 ;        /* possibly trailing pipes found */
        int     fc = 0 ;        /* quote or comma found */
        char    b[65536];       /* field buffer */
        for ( c = 1 ; c < argc ; c++ )
        {
                if ( !strcmp( argv[c], "-s" )
                  && ++c < argc
                  && strlen( argv[c] ) == 1 )
                {
                        sep = argv[c][0] ;
                        continue ;
                }
                fputs( usage, stderr );
                exit( 1 );
        }
        do
        {
                switch( c = getchar() )
                {
                case EOF:
                        if ( ferror( stdin ) )
                        {
                                perror( "stdin" );
                                exit( 1 );
                        }
                        continue ;      /* Out of loop */
                case '\n':
                        if ( fc )
                        {
                                if ( 0 > printf( "\"%.*s\"\r%c", cl, b, c ) )
                                {
                                        if ( !feof( stdout )
                                          || ferror( stdout ) )
                                        {
                                                perror( "printf()" );
                                                exit( 1 );
                                        }
                                        exit( 0 );
                                }
                                fc = 0 ;
                        }
                        else
                        {
                                if ( 0 > printf( "%.*s\r%c", cl, b, c ) )
                                {
                                        if ( !feof( stdout )
                                          || ferror( stdout ) )
                                        {
                                                perror( "printf()" );
                                                exit( 1 );
                                        }
                                        exit( 0 );
                                }
                        }
                        cl = 0 ;
                        fs = 0 ;
                        fp = 0 ;
                        continue ;
                case ' ':
                        if ( cl )
                                fs++ ;
                        continue ;
                case ',':
                        fc = 1 ;
                        break ;
                case '"':
                        while ( fp )
                        {
                                fp-- ;
                                if ( EOF == putchar( ',' ) )
                                {
                                        if ( ferror( stdout ) )
                                        {
                                                perror( "stdout" );
                                                exit( 1 );
                                        }
                                        exit( 0 );
                                }
                        }
                        while ( fs )
                        {
                                fs-- ;
                                if ( cl == 65536 )
                                {
                                        fprintf( stderr, "Field too long!\n" );
                                        exit( 1 );
                                }
                                b[ cl++ ] = ' ' ;
                        }
                        if ( cl == 65536 )
                        {
                                fprintf( stderr, "Field too long!\n" );
                                exit( 1 );
                        }
                        b[ cl++ ] = c ;
                        break ;
                default:
                        if ( c == sep )
                        {
                                if ( !cl )
                                {
                                        fp++ ;
                                        continue ;
                                }
                                while ( fp )
                                {
                                        fp-- ;
                                        if ( EOF == putchar( ',' ) )
                                        {
                                                if ( ferror( stdout ) )
                                                {
                                                        perror( "stdout" );
                                                        exit( 1 );
                                                }
                                                exit( 0 );
                                        }
                                }
                                c = ',' ;
                                if ( fc )
                                {
                                        if ( 0 > printf( "\"%.*s\"%c",
                                                                cl, b, c ) )
                                        {
                                                if ( !feof( stdout )
                                                  || ferror( stdout ) )
                                                {
                                                        perror( "printf()" );
                                                        exit( 1 );
                                                }
                                                exit( 0 );
                                        }
                                        fc = 0 ;
                                }
                                else
                                {
                                        if ( 0 > printf( "%.*s%c", cl, b, c ) )
                                        {
                                                if ( !feof( stdout )
                                                  || ferror( stdout ) )
                                                {
                                                        perror( "printf()" );
                                                        exit( 1 );
                                                }
                                                exit( 0 );
                                        }
                                }
                                cl = 0 ;
                                fs = 0 ;
                                fp = 0 ;
                                continue ;
                        }
                        while ( fp )
                        {
                                fp-- ;
                                if ( EOF == putchar( ',' ) )
                                {
                                        if ( ferror( stdout ) )
                                        {
                                                perror( "stdout" );
                                                exit( 1 );
                                        }
                                        exit( 0 );
                                }
                        }
                        while ( fs )
                        {
                                fs-- ;
                                if ( cl == 65536 )
                                {
                                        fprintf( stderr, "Field too long!\n" );
                                        exit( 1 );
                                }
                                b[ cl++ ] = ' ' ;
                        }
                        break ;
                }
                if ( cl == 65536 )
                {
                        fprintf( stderr, "Field too long!\n" );
                        exit( 1 );
                }
                b[ cl++ ] = c ;
        } while ( c != EOF );
        exit( 0 );
}