SQLite

typedef struct ArCommand ArCommand;
struct ArCommand {
  u8 eCmd;                        /* An AR_CMD_* value */
  u8 bVerbose;                    /* True if --verbose */
  u8 bZip;                        /* True if the archive is a ZIP */
  u8 bDryRun;                     /* True if --dry-run */
  u8 bAppend;                     /* True if --append */
  u8 fromCmdLine;                 /* Run from -A instead of .archive */
  int nArg;                       /* Number of command arguments */
  char *zSrcTable;                /* "sqlar", "zipfile($file)" or "zip" */
  const char *zFile;              /* --file argument, or NULL */
  const char *zDir;               /* --directory argument, or NULL */
  char **azArg;                   /* Array of command arguments */
  ShellState *p;                  /* Shell state */
  sqlite3 *db;                    /* Database containing the archive */

  return SQLITE_ERROR;
}

/*
** Print an error message for the .ar command to stderr and return 
** SQLITE_ERROR.
*/
static int arErrorMsg(ArCommand *pAr, const char *zFmt, ...){
  va_list ap;
  char *z;
  va_start(ap, zFmt);
  z = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
  utf8_printf(stderr, "Error: %s\n", z);
  if( pAr->fromCmdLine ){
    utf8_printf(stderr, "Use \"-A\" for more help\n");
  }else{
    utf8_printf(stderr, "Use \".archive --help\" for more help\n");
  }
  sqlite3_free(z);
  return SQLITE_ERROR;
}

/*
** Values for ArCommand.eCmd.
*/

  switch( eSwitch ){
    case AR_CMD_CREATE:
    case AR_CMD_EXTRACT:
    case AR_CMD_LIST:
    case AR_CMD_UPDATE:
    case AR_CMD_HELP:
      if( pAr->eCmd ){
        return arErrorMsg(pAr, "multiple command options");
      }
      pAr->eCmd = eSwitch;
      break;

    case AR_SWITCH_DRYRUN:
      pAr->bDryRun = 1;
      break;

  int nSwitch = sizeof(aSwitch) / sizeof(struct ArSwitch);
  struct ArSwitch *pEnd = &aSwitch[nSwitch];

  if( nArg<=1 ){
    return arUsage(stderr);
  }else{
    char *z = azArg[1];


    if( z[0]!='-' ){
      /* Traditional style [tar] invocation */
      int i;
      int iArg = 2;
      for(i=0; z[i]; i++){
        const char *zArg = 0;
        struct ArSwitch *pOpt;
        for(pOpt=&aSwitch[0]; pOpt<pEnd; pOpt++){
          if( z[i]==pOpt->cShort ) break;
        }
        if( pOpt==pEnd ){
          return arErrorMsg(pAr, "unrecognized option: %c", z[i]);
        }
        if( pOpt->bArg ){
          if( iArg>=nArg ){
            return arErrorMsg(pAr, "option requires an argument: %c",z[i]);
          }
          zArg = azArg[iArg++];
        }
        if( arProcessSwitch(pAr, pOpt->eSwitch, zArg) ) return SQLITE_ERROR;
      }
      pAr->nArg = nArg-iArg;
      if( pAr->nArg>0 ){

          for(i=1; i<n; i++){
            const char *zArg = 0;
            struct ArSwitch *pOpt;
            for(pOpt=&aSwitch[0]; pOpt<pEnd; pOpt++){
              if( z[i]==pOpt->cShort ) break;
            }
            if( pOpt==pEnd ){
              return arErrorMsg(pAr, "unrecognized option: %c", z[i]);
            }
            if( pOpt->bArg ){
              if( i<(n-1) ){
                zArg = &z[i+1];
                i = n;
              }else{
                if( iArg>=(nArg-1) ){
                  return arErrorMsg(pAr, "option requires an argument: %c",z[i]);
                }
                zArg = azArg[++iArg];
              }
            }
            if( arProcessSwitch(pAr, pOpt->eSwitch, zArg) ) return SQLITE_ERROR;
          }
        }else if( z[2]=='\0' ){

          const char *zArg = 0;             /* Argument for option, if any */
          struct ArSwitch *pMatch = 0;      /* Matching option */
          struct ArSwitch *pOpt;            /* Iterator */
          for(pOpt=&aSwitch[0]; pOpt<pEnd; pOpt++){
            const char *zLong = pOpt->zLong;
            if( (n-2)<=strlen30(zLong) && 0==memcmp(&z[2], zLong, n-2) ){
              if( pMatch ){
                return arErrorMsg(pAr, "ambiguous option: %s",z);
              }else{
                pMatch = pOpt;
              }
            }
          }

          if( pMatch==0 ){
            return arErrorMsg(pAr, "unrecognized option: %s", z);
          }
          if( pMatch->bArg ){
            if( iArg>=(nArg-1) ){
              return arErrorMsg(pAr, "option requires an argument: %s", z);
            }
            zArg = azArg[++iArg];
          }
          if( arProcessSwitch(pAr, pMatch->eSwitch, zArg) ) return SQLITE_ERROR;
        }
      }
    }

        );
      }else{
        utf8_printf(pAr->p->out, "%s\n", sqlite3_column_text(pSql, 0));
      }
    }
  }
  shellFinalize(&rc, pSql);
  sqlite3_free(zWhere);
  return rc;
}


/*
** Implementation of .ar "eXtract" command. 
*/

}

/*
** Implementation of ".ar" dot command.
*/
static int arDotCommand(
  ShellState *pState,             /* Current shell tool state */
  int fromCmdLine,                /* True if -A command-line option, not .ar cmd */
  char **azArg,                   /* Array of arguments passed to dot command */
  int nArg                        /* Number of entries in azArg[] */
){
  ArCommand cmd;
  int rc;
  memset(&cmd, 0, sizeof(cmd));
  cmd.fromCmdLine = fromCmdLine;
  rc = arParseCommand(azArg, nArg, &cmd);
  if( rc==SQLITE_OK ){
    int eDbType = SHELL_OPEN_UNSPEC;
    cmd.p = pState;
    cmd.db = pState->db;
    if( cmd.zFile ){
      eDbType = deduceDatabaseType(cmd.zFile, 1);

      }
      sqlite3_fileio_init(cmd.db, 0, 0);
      sqlite3_sqlar_init(cmd.db, 0, 0);
      sqlite3_create_function(cmd.db, "shell_putsnl", 1, SQLITE_UTF8, cmd.p,
                              shellPutsFunc, 0, 0);

    }
    if( cmd.zSrcTable==0 && cmd.bZip==0 && cmd.eCmd!=AR_CMD_HELP ){
      if( cmd.eCmd!=AR_CMD_CREATE
       && sqlite3_table_column_metadata(cmd.db,0,"sqlar","name",0,0,0,0,0)
      ){
        utf8_printf(stderr, "database does not contain an 'sqlar' table\n");
        rc = SQLITE_ERROR;
        goto end_ar_command;
      }

    }
  }else
#endif

#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB)
  if( c=='a' && strncmp(azArg[0], "archive", n)==0 ){
    open_db(p, 0);
    rc = arDotCommand(p, 0, azArg, nArg);
  }else
#endif

  if( (c=='b' && n>=3 && strncmp(azArg[0], "backup", n)==0)
   || (c=='s' && n>=3 && strncmp(azArg[0], "save", n)==0)
  ){
    const char *zDestFile = 0;

        utf8_printf(stderr, "Error: cannot mix regular SQL or dot-commands"
                            " with \"%s\"\n", z);
        return 1;
      }
      open_db(&data, 0);
      if( z[2] ){
        argv[i] = &z[2];
        arDotCommand(&data, 1, argv+(i-1), argc-(i-1));
      }else{
        arDotCommand(&data, 1, argv+i, argc-i);
      }
      readStdin = 0;
      break;
#endif
    }else{
      utf8_printf(stderr,"%s: Error: unknown option: %s\n", Argv0, z);
      raw_printf(stderr,"Use -help for a list of options.\n");