static void shellReset(
  int *pRc, 
  sqlite3_stmt *pStmt
){
  int rc = sqlite3_reset(pStmt);
  if( *pRc==SQLITE_OK ) *pRc = rc;
}

/*


















































































































** Implementation of .ar "eXtract" command. 
*/
static int arExtractCommand(ShellState *p, int bVerbose){
  const char *zSql1 = 
    "SELECT name, writefile(name, "
    "CASE WHEN (data AND sz>=0 AND sz!=length(data)) THEN uncompress(data) "
    "   ELSE data END, "
    "mode) FROM sqlar";
  const char *zSql2 = "SELECT name, mtime FROM sqlar"; 

................................................................................
  int rc = SQLITE_OK;

  memset(times, 0, sizeof(times));
  times[0].tv_sec = time(0);

  shellPrepare(p, &rc, zSql1, &pSql);
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
    if( bVerbose ){
      raw_printf(stdout, "%s\n", sqlite3_column_text(pSql, 0));
    }
  }
  shellFinalize(&rc, pSql);

  shellPrepare(p, &rc, zSql2, &pSql);
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
................................................................................
** Create the "sqlar" table in the database if it does not already exist.
** Then add each file in the azFile[] array to the archive. Directories
** are added recursively. If argument bVerbose is non-zero, a message is
** printed on stdout for each file archived.
*/
static int arCreateCommand(
  ShellState *p,                  /* Shell state pointer */
  char **azFile,                  /* Array of files to add to archive */
  int nFile,                      /* Number of entries in azFile[] */
  int bVerbose                    /* True to be verbose on stdout */
){
  const char *zSql = 
    "WITH f(n, m, t, d) AS ("
    "  SELECT name, mode, mtime, data FROM fsentry(:1) UNION ALL "
    "  SELECT n || '/' || name, mode, mtime, data "
    "      FROM f, fsdir(n) WHERE (m&?)"
    ") SELECT * FROM f";
................................................................................
  rc = sqlite3_exec(p->db, "SAVEPOINT ar;", 0, 0, 0);
  if( rc!=SQLITE_OK ) return rc;

  rc = sqlite3_exec(p->db, zSqlar, 0, 0, 0);
  shellPrepare(p, &rc, zInsert, &pInsert);
  shellPrepare(p, &rc, zSql, &pStmt);

  for(i=0; i<nFile && rc==SQLITE_OK; i++){
    sqlite3_bind_text(pStmt, 1, azFile[i], -1, SQLITE_STATIC);
    sqlite3_bind_int(pStmt, 2, S_IFDIR);
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
      int sz;
      const char *zName = (const char*)sqlite3_column_text(pStmt, 0);
      int mode = sqlite3_column_int(pStmt, 1);
      unsigned int mtime = sqlite3_column_int(pStmt, 2);

      if( bVerbose ){
        raw_printf(stdout, "%s\n", zName);
      }

      sqlite3_bind_text(pInsert, 1, zName, -1, SQLITE_STATIC);
      sqlite3_bind_int(pInsert, 2, mode);
      sqlite3_bind_int64(pInsert, 3, (sqlite3_int64)mtime);

................................................................................
** Implementation of ".ar" dot command.
*/
static int arDotCommand(
  ShellState *pState,             /* Current shell tool state */
  char **azArg,                   /* Array of arguments passed to dot command */
  int nArg                        /* Number of entries in azArg[] */
){
  int bVerbose = 0;
  char cmd = 0;
  int i;
  int n1;
  if( nArg<=1 ) goto usage;

  n1 = strlen(azArg[1]);
  for(i=0; i<n1; i++){
    char c = azArg[1][i];
    if( c=='c' || c=='x' ){
      if( cmd ) goto usage;
      cmd = c;
    }
    else if( c=='v' ){
      bVerbose = 1;
    }else{
      goto usage;
    }
  }

  if( cmd=='c' ){
    return arCreateCommand(pState, &azArg[2], nArg-2, bVerbose);
  }

  if( cmd=='x' ){
    if( nArg!=2 ) goto usage;
    return arExtractCommand(pState, bVerbose);
  }

 usage:
  raw_printf(stderr, "Usage %s sub-command ?args...?\n", azArg[0]);
  return SQLITE_ERROR;
}


/*
** If an input line begins with "." then invoke this routine to
** process that line.
**

static void shellReset(
  int *pRc, 
  sqlite3_stmt *pStmt
){
  int rc = sqlite3_reset(pStmt);
  if( *pRc==SQLITE_OK ) *pRc = rc;
}

/* 
** Structure representing a single ".ar" command.
*/
typedef struct ArCommand ArCommand;
struct ArCommand {
  int eCmd;                       /* An AR_CMD_* value */
  const char *zFile;              /* --file argument, or NULL */
  const char *zDir;               /* --directory argument, or NULL */
  int bVerbose;                   /* True if --verbose */
  int nArg;                       /* Number of command arguments */
  char **azArg;                   /* Array of command arguments */
};

/*
** Print a usage message for the .ar command to stderr and return SQLITE_ERROR.
*/
static int arUsage(void){
  /* todo */
  raw_printf(stderr, "error in .ar command line\n");
  return SQLITE_ERROR;
}

/*
** Values for ArCommand.eCmd.
*/
#define AR_CMD_CREATE  1
#define AR_CMD_EXTRACT 2
#define AR_CMD_LIST    3
#define AR_CMD_UPDATE  4

/*
** Parse the command line for an ".ar" command. The results are written into
** structure (*pAr). SQLITE_OK is returned if the command line is parsed
** successfully, otherwise an error message is written to stderr and 
** SQLITE_ERROR returned.
*/
static int arParseCommand(
  char **azArg,                   /* Array of arguments passed to dot command */
  int nArg,                       /* Number of entries in azArg[] */
  ArCommand *pAr                  /* Populate this object */
){
  if( nArg<=1 ){
    return arUsage();
  }else{
    char *z = azArg[1];
    memset(pAr, 0, sizeof(ArCommand));

    if( z[0]!='-' ){
      /* Traditional style [tar] invocation */
      int i;
      int iArg = 2;
      for(i=0; z[i]; i++){
        switch( z[i] ){
          case 'c':
            if( pAr->eCmd ) return arUsage();
            pAr->eCmd = AR_CMD_CREATE;
            break;
          case 'x':
            if( pAr->eCmd ) return arUsage();
            pAr->eCmd = AR_CMD_EXTRACT;
            break;
          case 't':
            if( pAr->eCmd ) return arUsage();
            pAr->eCmd = AR_CMD_LIST;
            break;
          case 'u':
            if( pAr->eCmd ) return arUsage();
            pAr->eCmd = AR_CMD_UPDATE;
            break;

          case 'v':
            pAr->bVerbose = 1;
            break;
          case 'f':
            if( iArg>=nArg ) return arUsage();
            pAr->zFile = azArg[iArg++];
            break;
          case 'C':
            if( iArg>=nArg ) return arUsage();
            pAr->zDir = azArg[iArg++];
            break;

          default:
            return arUsage();
        }
      }

      pAr->nArg = nArg-iArg;
      if( pAr->nArg>0 ){
        pAr->azArg = &azArg[iArg];
      }
    }
  }

  return SQLITE_OK;
}

/*
** Implementation of .ar "Update" command. 
*/
static int arUpdateCmd(ShellState *p, ArCommand *pAr){
  raw_printf(stderr, "todo...\n");
  return SQLITE_OK;
}

/*
** Implementation of .ar "lisT" command. 
*/
static int arListCommand(ShellState *p, ArCommand *pAr){
  raw_printf(stderr, "todo...\n");
  return SQLITE_OK;
}


/*
** Implementation of .ar "eXtract" command. 
*/
static int arExtractCommand(ShellState *p, ArCommand *pAr){
  const char *zSql1 = 
    "SELECT name, writefile(name, "
    "CASE WHEN (data AND sz>=0 AND sz!=length(data)) THEN uncompress(data) "
    "   ELSE data END, "
    "mode) FROM sqlar";
  const char *zSql2 = "SELECT name, mtime FROM sqlar"; 

................................................................................
  int rc = SQLITE_OK;

  memset(times, 0, sizeof(times));
  times[0].tv_sec = time(0);

  shellPrepare(p, &rc, zSql1, &pSql);
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
    if( pAr->bVerbose ){
      raw_printf(stdout, "%s\n", sqlite3_column_text(pSql, 0));
    }
  }
  shellFinalize(&rc, pSql);

  shellPrepare(p, &rc, zSql2, &pSql);
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
................................................................................
** Create the "sqlar" table in the database if it does not already exist.
** Then add each file in the azFile[] array to the archive. Directories
** are added recursively. If argument bVerbose is non-zero, a message is
** printed on stdout for each file archived.
*/
static int arCreateCommand(
  ShellState *p,                  /* Shell state pointer */
  ArCommand *pAr                  /* Command arguments and options */


){
  const char *zSql = 
    "WITH f(n, m, t, d) AS ("
    "  SELECT name, mode, mtime, data FROM fsentry(:1) UNION ALL "
    "  SELECT n || '/' || name, mode, mtime, data "
    "      FROM f, fsdir(n) WHERE (m&?)"
    ") SELECT * FROM f";
................................................................................
  rc = sqlite3_exec(p->db, "SAVEPOINT ar;", 0, 0, 0);
  if( rc!=SQLITE_OK ) return rc;

  rc = sqlite3_exec(p->db, zSqlar, 0, 0, 0);
  shellPrepare(p, &rc, zInsert, &pInsert);
  shellPrepare(p, &rc, zSql, &pStmt);

  for(i=0; i<pAr->nArg && rc==SQLITE_OK; i++){
    sqlite3_bind_text(pStmt, 1, pAr->azArg[i], -1, SQLITE_STATIC);
    sqlite3_bind_int(pStmt, 2, S_IFDIR);
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
      int sz;
      const char *zName = (const char*)sqlite3_column_text(pStmt, 0);
      int mode = sqlite3_column_int(pStmt, 1);
      unsigned int mtime = sqlite3_column_int(pStmt, 2);

      if( pAr->bVerbose ){
        raw_printf(stdout, "%s\n", zName);
      }

      sqlite3_bind_text(pInsert, 1, zName, -1, SQLITE_STATIC);
      sqlite3_bind_int(pInsert, 2, mode);
      sqlite3_bind_int64(pInsert, 3, (sqlite3_int64)mtime);

................................................................................
** Implementation of ".ar" dot command.
*/
static int arDotCommand(
  ShellState *pState,             /* Current shell tool state */
  char **azArg,                   /* Array of arguments passed to dot command */
  int nArg                        /* Number of entries in azArg[] */
){
  ArCommand cmd;
  int rc;
  rc = arParseCommand(azArg, nArg, &cmd);
  if( rc==SQLITE_OK ){
    switch( cmd.eCmd ){
      case AR_CMD_CREATE:
        rc = arCreateCommand(pState, &cmd);
        break;

      case AR_CMD_EXTRACT:
        rc = arExtractCommand(pState, &cmd);
        break;

      case AR_CMD_LIST:
        rc = arListCommand(pState, &cmd);
        break;

      default:
        assert( cmd.eCmd==AR_CMD_UPDATE );
        rc = arUpdateCmd(pState, &cmd);
        break;
    }
  }

  return rc;







}


/*
** If an input line begins with "." then invoke this routine to
** process that line.
**

# 2017 December 9
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# Test the shell tool ".ar" command.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix shell8
set CLI [test_find_cli]

proc populate_dir {dirname spec} {
  # First delete the current tree, if one exists.
  file delete -force $dirname
  
  # Recreate the root of the new tree.
  file mkdir $dirname

  # Add each file to the new tree.
  foreach {f d} $spec {
    set path [file join $dirname $f]
    file mkdir [file dirname $path]
    set fd [open $path w]
    puts -nonewline $fd $d
    close $fd
  }
}

proc dir_to_list {dirname} {
  set res [list]
  foreach f [glob -nocomplain $dirname/*] {
    set mtime [file mtime $f]
    set perm [file attributes $f -perm]
    set relpath [file join {*}[lrange [file split $f] 1 end]]
    lappend res 
    if {[file isdirectory $f]} {
      lappend res [list $relpath / $mtime $perm]
      lappend res {*}[dir_to_list $f]
    } else {
      set fd [open $f]
      set data [read $fd]
      close $fd
      lappend res [list $relpath $data $mtime $perm]
    }
  }
  lsort $res
}

proc dir_compare {d1 d2} {
  set l1 [dir_to_list $d1]
  set l2 [dir_to_list $d1]
  string compare $l1 $l2
}

populate_dir ar1 {
  file1 "abcd" 
  file2 "efgh"
  dir1/file3 "ijkl"
}

set expected [dir_to_list ar1]
# puts "# $expected"
do_test 1.1 {
  forcedelete test_ar.db

  catchcmd test_ar.db ".ar c ar1"
  file delete -force ar1
  catchcmd test_ar.db ".ar x"

  dir_to_list ar1
} $expected



finish_test