---
name: "Findlib"
section: "3"
platform: "linux"
package: "ocaml-findlib"
version: "0.6.2-4"
release: "Debian 3.0 (Woody)"
platforms: ["linux"]
url: "https://new.carta.tech/Findlib"
---

# Findlib(3)

## SIGNATURE

```
module Findlib :
  sig
    val package_directory : string -> string
    val package_property : string list -> string -> string -> string
    val package_ancestors : string list -> string -> string list
    val package_deep_ancestors : string list -> string list -> string list
    val default_location : unit -> string
    (* Note: This signature is incomplete. See findlib.mli for the
     * full signature.
     *)
  end
```

## PACKAGING

The Findlib module is part of the "findlib" package. In order to link  it in, it is sufficient to link "findlib" in, e.g.

```
ocamlfind ocamlc
options
 -package findlib -linkpkg
options
```

There are archives for the bytecode compiler and for the native  compiler; for single-threaded and for multi-threaded applications, and  there is a special addition for toploops.

## DESCRIPTION

The Findlib module is the primary interface of the findlib library. It  contains functions to lookup packages, to interpret  META\[File that specifies metainformation of OCaml packages\] files, and to determine the ancestors of  packages.

### Findlib.package\_directory pkg

```
val package_directory : string -> string
```

Gets the absolute path of the directory where the package  *pkg* is stored. The exception Not\_found is  raised if the package could not be found.  Other exceptions may occur as file I/O is done.

### Findlib.package\_property predicates pkg variable

```
val package_property : string list -> string -> string -> string
```

Determines the value of the  *variable*   defined in the  META\[File that specifies metainformation of OCaml packages\] file of package  *pkg* with the given set of  *predicates*. The exception Not\_found is  raised if the package or the variable could not be found. Other  exceptions may occur as file I/O is done.

**Examples**\
 Get the value of the "requires" variable of package "p" with an empty  set of predicates:

```
Findlib.package_property [] "p" "requires"
```

Get the value of the "archive" variable of package "p" for  multi-threaded bytecode applications:

```
Findlib.package_property [ "mt"; "byte" ] "p" "archive"
```

### Findlib.package\_ancestors predicates pkg

```
val package_ancestors : string list -> string -> string list
```

Determines the direct ancestors of package  *pkg* for the set of  *predicates*. The returned list has no  specific order. The exception Not\_found is raised if the package could  not be found. The exception Failure is raised if one of the ancestors  could not be found, or if a circular dependency has been  detected. Other exceptions may occur as file I/O is done.

### Findlib.package\_deep\_ancestors predicates pkglist

```
val package_deep_ancestors : string list -> string list -> string list
```

Determines the list of direct or indirect ancestors of the packages in  *pkglist* for the set of  *predicates*. The returned list is  topologically sorted.  The exception Not\_found is raised if the package could  not be found. The exception Failure is raised if one of the ancestors  could not be found, or if a circular dependency has been  detected. Other exceptions may occur as file I/O is done.

### Findlib.default\_location ()

```
val default_location : unit -> string
```

Gets the default location where new packages will be installed.