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Programming-Idioms

  • Kotlin
  • Go

Idiom #144 Check if file exists

Set boolean b to true if file at path fp exists on filesystem; false otherwise.

Beware that you should not do this and then in the next instruction assume the result is still valid, this is a race condition on any multitasking OS.

import "os"
_, err := os.Stat(fp)
b := !os.IsNotExist(err)

There's no specific existence check func in standard library, so we have to inspect an error return value.
import java.io.File;
b = File(fb).exists()
with Ada.Directories;
B : constant Boolean := Ada.Directories.Exists (FP);
New implementation...
< > ⌨
programming-idioms.org 
_, err := os.Stat(fp)
b := !os.IsNotExist(err)
b = File(fb).exists()
B : constant Boolean := Ada.Directories.Exists (FP);
bool b = access(_fp, F_OK) == 0
(.exists (io/file fp))
bool b = std::filesystem::exists(fp);
bool b = File.Exists(fp);
bool b = fp.exists;
var b = await File(fp).exists();
inquire (file=fp,exist=b)
b = doesFileExist fp
const b = fs.existsSync(fp);
let b = true;
try {
	await access(fp);
} catch {
	b = false;
}
try {
	Deno.statSync(fp)
} catch(_e) {console.error("File does not exist.")}
boolean b = new File(fb).exists();
$b = file_exists($fp);
b := FileExists(fp);
my $b = -f $fp;
b = Path(fp).exists()
b = os.path.exists(fp)
b = File.exist?(fp)
let b = std::path::Path::new(fp).exists();