shell.c

SQLite 2.8.6 源代码,用来在Linux/Unix/Windows上编译安装.它是一个小型的数据库,但是非常好用,速度也快,一般的数据库查询之类的操作据统计比MySQL,PostgreSQL

      int i, j;
      int nPrintCol, nPrintRow;
      for(i=1; i<=nRow; i++){
        if( azResult[i]==0 ) continue;
        len = strlen(azResult[i]);
        if( len>maxlen ) maxlen = len;
      }
      nPrintCol = 80/(maxlen+2);
      if( nPrintCol<1 ) nPrintCol = 1;
      nPrintRow = (nRow + nPrintCol - 1)/nPrintCol;
      for(i=0; i<nPrintRow; i++){
        for(j=i+1; j<=nRow; j+=nPrintRow){
          char *zSp = j<=nPrintRow ? "" : "  ";
          printf("%s%-*s", zSp, maxlen, azResult[j] ? azResult[j] : "");
        }
        printf("\n");
      }
    }
    sqlite_free_table(azResult);
  }else

  if( c=='t' && n>1 && strncmp(azArg[0], "timeout", n)==0 && nArg>=2 ){
    open_db(p);
    sqlite_busy_timeout(p->db, atoi(azArg[1]));
  }else

  if( c=='w' && strncmp(azArg[0], "width", n)==0 ){
    int j;
    for(j=1; j<nArg && j<ArraySize(p->colWidth); j++){
      p->colWidth[j-1] = atoi(azArg[j]);
    }
  }else

  {
    fprintf(stderr, "unknown command or invalid arguments: "
      " \"%s\". Enter \".help\" for help\n", azArg[0]);
  }

  return rc;
}

/*
** Return TRUE if the last non-whitespace character in z[] is a semicolon.
** z[] is N characters long.
*/
static int _ends_with_semicolon(const char *z, int N){
  while( N>0 && isspace(z[N-1]) ){ N--; }
  return N>0 && z[N-1]==';';
}

/*
** Test to see if a line consists entirely of whitespace.
*/
static int _all_whitespace(const char *z){
  for(; *z; z++){
    if( isspace(*z) ) continue;
    if( *z=='/' && z[1]=='*' ){
      z += 2;
      while( *z && (*z!='*' || z[1]!='/') ){ z++; }
      if( *z==0 ) return 0;
      z++;
      continue;
    }
    if( *z=='-' && z[1]=='-' ){
      z += 2;
      while( *z && *z!='\n' ){ z++; }
      if( *z==0 ) return 1;
      continue;
    }
    return 0;
  }
  return 1;
}

/*
** Return TRUE if the line typed in is an SQL command terminator other
** than a semi-colon.  The SQL Server style "go" command is understood
** as is the Oracle "/".
*/
static int _is_command_terminator(const char *zLine){
  extern int sqliteStrNICmp(const char*,const char*,int);
  while( isspace(*zLine) ){ zLine++; };
  if( zLine[0]=='/' && _all_whitespace(&zLine[1]) ) return 1;  /* Oracle */
  if( sqliteStrNICmp(zLine,"go",2)==0 && _all_whitespace(&zLine[2]) ){
    return 1;  /* SQL Server */
  }
  return 0;
}

/*
** Read input from *in and process it.  If *in==0 then input
** is interactive - the user is typing it it.  Otherwise, input
** is coming from a file or device.  A prompt is issued and history
** is saved only if input is interactive.  An interrupt signal will
** cause this routine to exit immediately, unless input is interactive.
*/
static void process_input(struct callback_data *p, FILE *in){
  char *zLine;
  char *zSql = 0;
  int nSql = 0;
  char *zErrMsg;
  int rc;
  while( fflush(p->out), (zLine = one_input_line(zSql, in))!=0 ){
    if( seenInterrupt ){
      if( in!=0 ) break;
      seenInterrupt = 0;
    }
    if( p->echoOn ) printf("%s\n", zLine);
    if( (zSql==0 || zSql[0]==0) && _all_whitespace(zLine) ) continue;
    if( zLine && zLine[0]=='.' && nSql==0 ){
      int rc = do_meta_command(zLine, p);
      free(zLine);
      if( rc ) break;
      continue;
    }
    if( _is_command_terminator(zLine) ){
      strcpy(zLine,";");
    }
    if( zSql==0 ){
      int i;
      for(i=0; zLine[i] && isspace(zLine[i]); i++){}
      if( zLine[i]!=0 ){
        nSql = strlen(zLine);
        zSql = malloc( nSql+1 );
        strcpy(zSql, zLine);
      }
    }else{
      int len = strlen(zLine);
      zSql = realloc( zSql, nSql + len + 2 );
      if( zSql==0 ){
        fprintf(stderr,"%s: out of memory!\n", Argv0);
        exit(1);
      }
      strcpy(&zSql[nSql++], "\n");
      strcpy(&zSql[nSql], zLine);
      nSql += len;
    }
    free(zLine);
    if( zSql && _ends_with_semicolon(zSql, nSql) && sqlite_complete(zSql) ){
      p->cnt = 0;
      open_db(p);
      rc = sqlite_exec(p->db, zSql, callback, p, &zErrMsg);
      if( rc || zErrMsg ){
        if( in!=0 && !p->echoOn ) printf("%s\n",zSql);
        if( zErrMsg!=0 ){
          printf("SQL error: %s\n", zErrMsg);
          free(zErrMsg);
          zErrMsg = 0;
        }else{
          printf("SQL error: %s\n", sqlite_error_string(rc));
        }
      }
      free(zSql);
      zSql = 0;
      nSql = 0;
    }
  }
  if( zSql ){
    if( !_all_whitespace(zSql) ) printf("Incomplete SQL: %s\n", zSql);
    free(zSql);
  }
}

/*
** Return a pathname which is the user's home directory.  A
** 0 return indicates an error of some kind.  Space to hold the
** resulting string is obtained from malloc().  The calling
** function should free the result.
*/
static char *find_home_dir(void){
  char *home_dir = NULL;

#if !defined(_WIN32) && !defined(WIN32) && !defined(__MACOS__)
  struct passwd *pwent;
  uid_t uid = getuid();
  if( (pwent=getpwuid(uid)) != NULL) {
    home_dir = pwent->pw_dir;
  }
#endif

#ifdef __MACOS__
  char home_path[_MAX_PATH+1];
  home_dir = getcwd(home_path, _MAX_PATH);
#endif

  if (!home_dir) {
    home_dir = getenv("HOME");
    if (!home_dir) {
      home_dir = getenv("HOMEPATH"); /* Windows? */
    }
  }

#if defined(_WIN32) || defined(WIN32)
  if (!home_dir) {
    home_dir = "c:";
  }
#endif

  if( home_dir ){
    char *z = malloc( strlen(home_dir)+1 );
    if( z ) strcpy(z, home_dir);
    home_dir = z;
  }

  return home_dir;
}

/*
** Read input from the file given by sqliterc_override.  Or if that
** parameter is NULL, take input from ~/.sqliterc
*/
static void process_sqliterc(struct callback_data *p, char *sqliterc_override){
  char *home_dir = NULL;
  char *sqliterc = sqliterc_override;
  FILE *in = NULL;

  if (sqliterc == NULL) {
    home_dir = find_home_dir();
    if( home_dir==0 ){
      fprintf(stderr,"%s: cannot locate your home directory!\n", Argv0);
      return;
    }
    sqliterc = malloc(strlen(home_dir) + 15);
    if( sqliterc==0 ){
      fprintf(stderr,"%s: out of memory!\n", Argv0);
      exit(1);
    }
    sprintf(sqliterc,"%s/.sqliterc",home_dir);
    free(home_dir);
  }
  in = fopen(sqliterc,"r");
  if(in && isatty(fileno(stdout))) {
    printf("Loading resources from %s\n",sqliterc);
    process_input(p,in);
    fclose(in);
  }
  return;
}

/*
** Show available command line options
*/
static const char zOptions[] = 
  "   -init filename       read/process named file\n"
  "   -echo                print commands before execution\n"
  "   -[no]header          turn headers on or off\n"
  "   -column              set output mode to 'column'\n"
  "   -html                set output mode to HTML\n"
  "   -line                set output mode to 'line'\n"
  "   -list                set output mode to 'list'\n"
  "   -separator 'x'       set output field separator (|)\n"
  "   -nullvalue 'text'    set text string for NULL values\n"
  "   -version             show SQLite version\n"
  "   -help                show this text, also show dot-commands\n"
;
static void usage(int showDetail){
  fprintf(stderr, "Usage: %s [OPTIONS] FILENAME [SQL]\n", Argv0);
  if( showDetail ){
    fprintf(stderr, "Options are:\n%s", zOptions);
  }else{
    fprintf(stderr, "Use the -help option for additional information\n");
  }
  exit(1);
}

/*
** Initialize the state information in data
*/
void main_init(struct callback_data *data) {
  memset(data, 0, sizeof(*data));
  data->mode = MODE_List;
  strcpy(data->separator,"|");
  data->showHeader = 0;
  strcpy(mainPrompt,"sqlite> ");
  strcpy(continuePrompt,"   ...> ");
}

int main(int argc, char **argv){
  char *zErrMsg = 0;
  struct callback_data data;
  int origArgc = argc;
  char **origArgv = argv;
  int i;
  extern int sqliteOsFileExists(const char*);

#ifdef __MACOS__
  argc = ccommand(&argv);
  origArgc = argc;
  origArgv = argv;
#endif

  Argv0 = argv[0];
  main_init(&data);

  /* Make sure we have a valid signal handler early, before anything
  ** else is done.
  */
#ifdef SIGINT
  signal(SIGINT, interrupt_handler);
#endif

  /* Locate the name of the database file
  */
  for(i=1; i<argc; i++){
    if( argv[i][0]!='-' ) break;
    if( strcmp(argv[i],"-separator")==0 || strcmp(argv[i],"-nullvalue")==0 ){
      i++;
    }
  }
  data.zDbFilename = i<argc ? argv[i] : ":memory:";
  data.out = stdout;

  /* Go ahead and open the database file if it already exists.  If the
  ** file does not exist, delay opening it.  This prevents empty database
  ** files from being created if a user mistypes the database name argument
  ** to the sqlite command-line tool.
  */
  if( sqliteOsFileExists(data.zDbFilename) ){
    open_db(&data);
  }

  /* Process the ~/.sqliterc file, if there is one
  */
  process_sqliterc(&data,NULL);

  /* Process command-line options
  */
  while( argc>=2 && argv[1][0]=='-' ){
    if( argc>=3 && strcmp(argv[1],"-init")==0 ){
      /* If we get a -init to do, we have to pretend that
      ** it replaced the .sqliterc file. Soooo, in order to
      ** do that we need to start from scratch...*/
      main_init(&data);

      /* treat this file as the sqliterc... */
      process_sqliterc(&data,argv[2]);

      /* fix up the command line so we do not re-read
      ** the option next time around... */
      {
        int i = 1;
        for(i=1;i<=argc-2;i++) {
          argv[i] = argv[i+2];
        }
      }
      origArgc-=2;

      /* and reset the command line options to be re-read.*/
      argv = origArgv;
      argc = origArgc;

    }else if( strcmp(argv[1],"-html")==0 ){
      data.mode = MODE_Html;
      argc--;
      argv++;
    }else if( strcmp(argv[1],"-list")==0 ){
      data.mode = MODE_List;
      argc--;
      argv++;
    }else if( strcmp(argv[1],"-line")==0 ){
      data.mode = MODE_Line;
      argc--;
      argv++;
    }else if( strcmp(argv[1],"-column")==0 ){
      data.mode = MODE_Column;
      argc--;
      argv++;
    }else if( argc>=3 && strcmp(argv[1],"-separator")==0 ){
      sprintf(data.separator,"%.*s",(int)sizeof(data.separator)-1,argv[2]);
      argc -= 2;
      argv += 2;
    }else if( argc>=3 && strcmp(argv[1],"-nullvalue")==0 ){
      sprintf(data.nullvalue,"%.*s",(int)sizeof(data.nullvalue)-1,argv[2]);
      argc -= 2;
      argv += 2;
    }else if( strcmp(argv[1],"-header")==0 ){
      data.showHeader = 1;
      argc--;
      argv++;
    }else if( strcmp(argv[1],"-noheader")==0 ){
      data.showHeader = 0;
      argc--;
      argv++;
    }else if( strcmp(argv[1],"-echo")==0 ){
      data.echoOn = 1;
      argc--;
      argv++;
    }else if( strcmp(argv[1],"-version")==0 ){
      printf("%s\n", sqlite_version);
      return 1;
    }else if( strcmp(argv[1],"-help")==0 ){
      usage(1);
    }else{
      fprintf(stderr,"%s: unknown option: %s\n", Argv0, argv[1]);
      fprintf(stderr,"Use -help for a list of options.\n");
      return 1;
    }
  }

  if( argc<2 ){
    usage(0);
  }else if( argc==3 ){
    /* Run just the command that follows the database name
    */
    if( argv[2][0]=='.' ){
      do_meta_command(argv[2], &data);
      exit(0);
    }else{
      int rc;
      open_db(&data);
      rc = sqlite_exec(db, argv[2], callback, &data, &zErrMsg);
      if( rc!=0 && zErrMsg!=0 ){
        fprintf(stderr,"SQL error: %s\n", zErrMsg);
        exit(1);
      }
    }
  }else{
    /* Run commands received from standard input
    */
    if( isatty(fileno(stdout)) && isatty(fileno(stdin)) ){
      char *zHome;
      char *zHistory = 0;
      printf(
        "SQLite version %s\n"
        "Enter \".help\" for instructions\n",
        sqlite_version
      );
      zHome = find_home_dir();
      if( zHome && (zHistory = malloc(strlen(zHome)+20))!=0 ){
        sprintf(zHistory,"%s/.sqlite_history", zHome);
      }
      if( zHistory ) read_history(zHistory);
      process_input(&data, 0);
      if( zHistory ){
        stifle_history(100);
        write_history(zHistory);
      }
    }else{
      process_input(&data, stdin);
    }
  }
  set_table_name(&data, 0);
  if( db ) sqlite_close(db);
  return 0;
}