path: root/man/go-list.1

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.TH GO-LIST 1 "2022-08-02"
.\" Please adjust this date whenever revising the manpage.
.SH NAME
go-list \- list packages or modules
.SH SYNOPSIS
.B go list
.RB [ \-f
.IR format ]
.RB [ \-json ]
.RB [ \-m ]
.RI [ "list flags" ]
.RI [ "build flags" ]
.RI [ packages ]
.SH DESCRIPTION
List lists the packages named by the import paths, one per line.
.br
The most commonly-used flags are \-f and \-json, which control the form
of the output printed for each package. Other list flags, documented below,
control more specific details.
.P
The default output shows the package import path:

.Vb 6
\&      bytes
\&      encoding/json
\&      github.com/gorilla/mux
\&      golang.org/x/net/html
.Ve
.SH OPTIONS
.TP
.B \-f
The \-f flag specifies an alternate format for the list, using the
syntax of package template.  The default output is equivalent
to \-f '{{.ImportPath}}'.  The struct being passed to the template is:

.Vb 6
\&    type Package struct {
\&        Dir           string   // directory containing package sources
\&        ImportPath    string   // import path of package in dir
\&        ImportComment string   // path in import comment on package statement
\&        Name          string   // package name
\&        Doc           string   // package documentation string
\&        Target        string   // install path
\&        Shlib         string   // the shared library that contains this package (only set when -linkshared)
\&        Goroot        bool     // is this package in the Go root?
\&        Standard      bool     // is this package part of the standard Go library?
\&        Stale         bool     // would 'go install' do anything for this package?
\&        StaleReason   string   // explanation for Stale==true
\&        Root          string   // Go root or Go path dir containing this package
\&        ConflictDir   string   // this directory shadows Dir in $GOPATH
\&        BinaryOnly    bool     // binary-only package (no longer supported)
\&        ForTest       string   // package is only for use in named test
\&        Export        string   // file containing export data (when using -export)
\&        BuildID       string   // build ID of the compiled package (when using -export)
\&        Module        *Module  // info about package's containing module, if any (can be nil)
\&        Match         []string // command-line patterns matching this package
\&        DepOnly       bool     // package is only a dependency, not explicitly listed
\&
\&        // Source files
\&        GoFiles         []string   // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles)
\&        CgoFiles        []string   // .go source files that import "C"
\&        CompiledGoFiles []string   // .go files presented to compiler (when using -compiled)
\&        IgnoredGoFiles  []string   // .go source files ignored due to build constraints
\&        IgnoredOtherFiles []string // non-.go source files ignored due to build constraints
\&        CFiles          []string   // .c source files
\&        CXXFiles        []string   // .cc, .cxx and .cpp source files
\&        MFiles          []string   // .m source files
\&        HFiles          []string   // .h, .hh, .hpp and .hxx source files
\&        FFiles          []string   // .f, .F, .for and .f90 Fortran source files
\&        SFiles          []string   // .s source files
\&        SwigFiles       []string   // .swig files
\&        SwigCXXFiles    []string   // .swigcxx files
\&        SysoFiles       []string   // .syso object files to add to archive
\&        TestGoFiles     []string   // _test.go files in package
\&        XTestGoFiles    []string   // _test.go files outside package
\&
\&        // Embedded files
\&        EmbedPatterns      []string // //go:embed patterns
\&        EmbedFiles         []string // files matched by EmbedPatterns
\&        TestEmbedPatterns  []string // //go:embed patterns in TestGoFiles
\&        TestEmbedFiles     []string // files matched by TestEmbedPatterns
\&        XTestEmbedPatterns []string // //go:embed patterns in XTestGoFiles
\&        XTestEmbedFiles    []string // files matched by XTestEmbedPatterns
\&
\&        // Cgo directives
\&        CgoCFLAGS    []string // cgo: flags for C compiler
\&        CgoCPPFLAGS  []string // cgo: flags for C preprocessor
\&        CgoCXXFLAGS  []string // cgo: flags for C++ compiler
\&        CgoFFLAGS    []string // cgo: flags for Fortran compiler
\&        CgoLDFLAGS   []string // cgo: flags for linker
\&        CgoPkgConfig []string // cgo: pkg-config names
\&
\&        // Dependency information
\&        Imports      []string          // import paths used by this package
\&        ImportMap    map[string]string // map from source import to ImportPath (identity entries omitted)
\&        Deps         []string          // all (recursively) imported dependencies
\&        TestImports  []string          // imports from TestGoFiles
\&        XTestImports []string          // imports from XTestGoFiles
\&
\&        // Error information
\&        Incomplete bool            // this package or a dependency has an error
\&        Error      *PackageError   // error loading package
\&        DepsErrors []*PackageError // errors loading dependencies
\&    }
.Ve

Packages stored in vendor directories report an ImportPath that includes the
path to the vendor directory (for example, "d/vendor/p" instead of "p"),
so that the ImportPath uniquely identifies a given copy of a package.
The Imports, Deps, TestImports, and XTestImports lists also contain these
expanded import paths. See golang.org/s/go15vendor for more about vendoring.

The error information, if any, is

.Vb 6
\&    type PackageError struct {
\&        ImportStack   []string // shortest path from package named on command line to this one
\&        Pos           string   // position of error (if present, file:line:col)
\&        Err           string   // the error itself
\&    }
.Ve

The module information is a Module struct, defined in the discussion
of list \-m below.

The template function "join" calls strings.Join.

The template function "context" returns the build context, defined as:

.Vb 6
\&    type Context struct {
\&        GOARCH        string   // target architecture
\&        GOOS          string   // target operating system
\&        GOROOT        string   // Go root
\&        GOPATH        string   // Go path
\&        CgoEnabled    bool     // whether cgo can be used
\&        UseAllFiles   bool     // use files regardless of +build lines, file names
\&        Compiler      string   // compiler to assume when computing target paths
\&        BuildTags     []string // build constraints to match in +build lines
\&        ToolTags      []string // toolchain-specific build constraints
\&        ReleaseTags   []string // releases the current release is compatible with
\&        InstallSuffix string   // suffix to use in the name of the install dir
\&    }
.Ve

For more information about the meaning of these fields see the documentation
for the go/build package's Context type.
.TP
.B \-json
The \-json flag causes the package data to be printed in JSON format
instead of using the template format. The JSON flag can optionally be
provided with a set of comma-separated required field names to be output.
If so, those required fields will always appear in JSON output, but
others may be omitted to save work in computing the JSON struct.
.TP
.B \-compiled
The \-compiled flag causes list to set CompiledGoFiles to the Go source
files presented to the compiler. Typically this means that it repeats
the files listed in GoFiles and then also adds the Go code generated
by processing CgoFiles and SwigFiles. The Imports list contains the
union of all imports from both GoFiles and CompiledGoFiles.
.TP
.B \-deps
The \-deps flag causes list to iterate over not just the named packages
but also all their dependencies. It visits them in a depth-first post-order
traversal, so that a package is listed only after all its dependencies.
Packages not explicitly listed on the command line will have the DepOnly
field set to true.
.TP
.B \-e
The \-e flag changes the handling of erroneous packages, those that
cannot be found or are malformed.  By default, the list command
prints an error to standard error for each erroneous package and
omits the packages from consideration during the usual printing.
With the \-e flag, the list command never prints errors to standard
error and instead processes the erroneous packages with the usual
printing.  Erroneous packages will have a non-empty ImportPath and
a non-nil Error field; other information may or may not be missing
(zeroed).
.TP
.B \-export
The \-export flag causes list to set the Export field to the name of a
file containing up-to-date export information for the given package,
and the BuildID field to the build ID of the compiled package.
.TP
.B \-find
The \-find flag causes list to identify the named packages but not
resolve their dependencies: the Imports and Deps lists will be empty.
.TP
.B \-test
The \-test flag causes list to report not only the named packages
but also their test binaries (for packages with tests), to convey to
source code analysis tools exactly how test binaries are constructed.
The reported import path for a test binary is the import path of
the package followed by a ".test" suffix, as in "math/rand.test".
When building a test, it is sometimes necessary to rebuild certain
dependencies specially for that test (most commonly the tested
package itself). The reported import path of a package recompiled
for a particular test binary is followed by a space and the name of
the test binary in brackets, as in "math/rand [math/rand.test]"
or "regexp [sort.test]". The ForTest field is also set to the name
of the package being tested ("math/rand" or "sort" in the previous
examples).
.P
The Dir, Target, Shlib, Root, ConflictDir, and Export file paths
are all absolute paths.
.P
By default, the lists GoFiles, CgoFiles, and so on hold names of files in Dir
(that is, paths relative to Dir, not absolute paths).
The generated files added when using the \-compiled and \-test flags
are absolute paths referring to cached copies of generated Go source files.
Although they are Go source files, the paths may not end in ".go".
.TP
.B \-m
The \-m flag causes list to list modules instead of packages.

When listing modules, the \-f flag still specifies a format template
applied to a Go struct, but now a Module struct:

.Vb 6
\&    type Module struct {
\&        Path       string        // module path
\&        Query      string        // version query corresponding to this version
\&        Version    string        // module version
\&        Versions   []string      // available module versions
\&        Replace    *Module       // replaced by this module
\&        Time       *time.Time    // time version was created
\&        Update     *Module       // available update (with -u)
\&        Main       bool          // is this the main module?
\&        Indirect   bool          // module is only indirectly needed by main module
\&        Dir        string        // directory holding local copy of files, if any
\&        GoMod      string        // path to go.mod file describing module, if any
\&        GoVersion  string        // go version used in module
\&        Retracted  []string      // retraction information, if any (with -retracted or -u)
\&        Deprecated string        // deprecation message, if any (with -u)
\&        Error      *ModuleError  // error loading module
\&        Origin     any           // provenance of module
\&        Reuse      bool          // reuse of old module info is safe
\&    }
\&
\&    type ModuleError struct {
\&        Err string // the error itself
\&    }
.Ve

The file GoMod refers to may be outside the module directory if the
module is in the module cache or if the \-modfile flag is used.

The default output is to print the module path and then
information about the version and replacement if any.
For example, 'go list \-m all' might print:

.Vb 6
\&    my/main/module
\&    golang.org/x/text v0.3.0 => /tmp/text
\&    rsc.io/pdf v0.1.1
.Ve

The Module struct has a String method that formats this
line of output, so that the default format is equivalent
to \-f '{{.String}}'.

Note that when a module has been replaced, its Replace field
describes the replacement module, and its Dir field is set to
the replacement's source code, if present. (That is, if Replace
is non-nil, then Dir is set to Replace.Dir, with no access to
the replaced source code.)
.TP
.B \-u
The \-u flag adds information about available upgrades.
When the latest version of a given module is newer than
the current one, list \-u sets the Module's Update field
to information about the newer module. list \-u will also set
the module's Retracted field if the current version is retracted.
The Module's String method indicates an available upgrade by
formatting the newer version in brackets after the current version.
If a version is retracted, the string "(retracted)" will follow it.
For example, 'go list \-m \-u all' might print:

.Vb 6
\&    my/main/module
\&    golang.org/x/text v0.3.0 [v0.4.0] => /tmp/text
\&    rsc.io/pdf v0.1.1 (retracted) [v0.1.2]
.Ve

(For tools, 'go list \-m \-u \-json all' may be more convenient to parse.)
.TP
.B \-versions
The \-versions flag causes list to set the Module's Versions field
to a list of all known versions of that module, ordered according
to semantic versioning, earliest to latest. The flag also changes
the default output format to display the module path followed by the
space-separated version list.
.TP
.B \-retracted
The \-retracted flag causes list to report information about retracted
module versions. When \-retracted is used with \-f or \-json, the Retracted
field will be set to a string explaining why the version was retracted.
The string is taken from comments on the retract directive in the
module's go.mod file. When \-retracted is used with \-versions, retracted
versions are listed together with unretracted versions. The \-retracted
flag may be used with or without \-m.
.P
The arguments to list \-m are interpreted as a list of modules, not packages.
The main module is the module containing the current directory.
The active modules are the main module and its dependencies.
With no arguments, list \-m shows the main module.
With arguments, list \-m shows the modules specified by the arguments.
Any of the active modules can be specified by its module path.
The special pattern "all" specifies all the active modules, first the main
module and then dependencies sorted by module path.
A pattern containing "..." specifies the active modules whose
module paths match the pattern.
A query of the form path@version specifies the result of that query,
which is not limited to active modules.
See 'go help modules' for more about module queries.
.P
The template function "module" takes a single string argument
that must be a module path or query and returns the specified
module as a Module struct. If an error occurs, the result will
be a Module struct with a non-nil Error field.
.P
When using \-m, the \-reuse=old.json flag accepts the name of file containing
the JSON output of a previous \(oqgo list \-m \-json\(cq invocation with the
same set of modifier flags (such as \-u, \-retracted, and \-versions).
The go command may use this file to determine that a module is unchanged
since the previous invocation and avoid redownloading information about it.
Modules that are not redownloaded will be marked in the new output by
setting the Reuse field to true. Normally the module cache provides this
kind of reuse automatically; the \-reuse flag can be useful on systems that
do not preserve the module cache.
.P
For more about build flags, see \fBgo-build\fP(1) or 'go help build'.
.P
For more about specifying packages, see \fBgo-packages\fP(7) or 'go help packages'.
.P
For more about modules, see https://golang.org/ref/mod.
.SH AUTHOR
This manual page was written by Michael Stapelberg <stapelberg@debian.org>
and is maintained by the
Debian Go Compiler Team <team+go-compiler@tracker.debian.org>
based on the output of 'go help list'
for the Debian project (and may be used by others).