exists

Syntax

exists(path)

Arguments

path is a string or a string vector, indicating the path of a file (or files) or a folder (or folders).

Details

Check if the specified file (or files) or folder (or folders) exists. In the distributed files system, check if the specified folder (or folders) exists.

Examples

$ t=table(1..10 as ID, rand(1.0, 10) as x);
$ saveText(t, "C:/DolphinDB/Data/t.txt");

$ exists("C:/DolphinDB/Data/t.txt");
1
$ exists("C:/DolphinDB/Data/t1.txt");
0
$ exists("C:/DolphinDB/Data");
1

$ exists(["C:/DolphinDB/Data/t.txt","C:/DolphinDB/Data/t1.txt","C:/DolphinDB/Data"]);
[1,0,1]

To check if a folder (or folders) exists in the distributed files system (the following script must be executed at a data node in a cluster):

$ n=1000000
$ ID=rand(10, n)
$ dates=2017.08.07..2017.08.11
$ date=rand(dates, n)
$ x=rand(10.0, n)
$ t=table(ID, date, x)

$ db = database("dfs://valueDB", VALUE, 2017.08.07..2017.08.11)
$ pt = db.createPartitionedTable(t, `pt, `date);
$ pt.append!(t);

$ exists("dfs://valueDB/20170807");
1