file-exists? - test if a file exists

(import (rnrs))                     ;R6RS
(import (rnrs files))               ;R6RS
(import (scheme file))              ;R7RS

(file-exists? filename)

This procedure returns #t if the named file exists at the time the procedure is called and #f otherwise.

Returns a single boolean object.

;; Assuming a typical Unix-like system
(file-exists? "/dev/null")
          => #t

This procedure is used to check if a file exists before trying to perform some operation on it. One common usage is in a Scheme implementation's library loader, which needs to check if a base filename exists in one of multiple paths, often trying different file extensions.

This procedure is absent from R5RS and earlier reports.

This procedure can raise exceptions with the following condition types:

&assertion (R6RS)

The wrong number of arguments was passed or an argument was outside its domain.

R7RS

The assertions described above are errors. Implementations may signal an error, extend the procedure's domain of definition to include such arguments, or fail catastrophically.

delete-file(3scm), open-input-file(3scm), open-output-file(3scm)

R6RS, R7RS

This procedure is new in R6RS and its description was copied into R7RS. It is absent from previous reports. Early Scheme running on MacLISP could use the procedure allfiles to check if a file exists.

This page is part of the scheme-manpages project. It includes materials from the RnRS documents. More information can be found at https://weinholt.se/scheme/manpages/.

Programs that check if a file exist and then immediately operate on it are prone to race conditions. The file may have been removed immediately after this procedure checked for its existence, or it might have been created. This is often not a problem.