1 // Copyright 2011 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package main 6 7 import ( 8 "bufio" 9 "encoding/json" 10 "io" 11 "os" 12 "strings" 13 "text/template" 14 ) 15 16 var cmdList = &Command{ 17 UsageLine: "list [-e] [-f format] [-json] [build flags] [packages]", 18 Short: "list packages", 19 Long: ` 20 List lists the packages named by the import paths, one per line. 21 22 The default output shows the package import path: 23 24 bytes 25 encoding/json 26 github.com/gorilla/mux 27 golang.org/x/net/html 28 29 The -f flag specifies an alternate format for the list, using the 30 syntax of package template. The default output is equivalent to -f 31 '{{.ImportPath}}'. The struct being passed to the template is: 32 33 type Package struct { 34 Dir string // directory containing package sources 35 ImportPath string // import path of package in dir 36 ImportComment string // path in import comment on package statement 37 Name string // package name 38 Doc string // package documentation string 39 Target string // install path 40 Shlib string // the shared library that contains this package (only set when -linkshared) 41 Goroot bool // is this package in the Go root? 42 Standard bool // is this package part of the standard Go library? 43 Stale bool // would 'go install' do anything for this package? 44 StaleReason string // explanation for Stale==true 45 Root string // Go root or Go path dir containing this package 46 ConflictDir string // this directory shadows Dir in $GOPATH 47 BinaryOnly bool // binary-only package: cannot be recompiled from sources 48 49 // Source files 50 GoFiles []string // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles) 51 CgoFiles []string // .go sources files that import "C" 52 IgnoredGoFiles []string // .go sources ignored due to build constraints 53 CFiles []string // .c source files 54 CXXFiles []string // .cc, .cxx and .cpp source files 55 MFiles []string // .m source files 56 HFiles []string // .h, .hh, .hpp and .hxx source files 57 FFiles []string // .f, .F, .for and .f90 Fortran source files 58 SFiles []string // .s source files 59 SwigFiles []string // .swig files 60 SwigCXXFiles []string // .swigcxx files 61 SysoFiles []string // .syso object files to add to archive 62 TestGoFiles []string // _test.go files in package 63 XTestGoFiles []string // _test.go files outside package 64 65 // Cgo directives 66 CgoCFLAGS []string // cgo: flags for C compiler 67 CgoCPPFLAGS []string // cgo: flags for C preprocessor 68 CgoCXXFLAGS []string // cgo: flags for C++ compiler 69 CgoFFLAGS []string // cgo: flags for Fortran compiler 70 CgoLDFLAGS []string // cgo: flags for linker 71 CgoPkgConfig []string // cgo: pkg-config names 72 73 // Dependency information 74 Imports []string // import paths used by this package 75 Deps []string // all (recursively) imported dependencies 76 TestImports []string // imports from TestGoFiles 77 XTestImports []string // imports from XTestGoFiles 78 79 // Error information 80 Incomplete bool // this package or a dependency has an error 81 Error *PackageError // error loading package 82 DepsErrors []*PackageError // errors loading dependencies 83 } 84 85 Packages stored in vendor directories report an ImportPath that includes the 86 path to the vendor directory (for example, "d/vendor/p" instead of "p"), 87 so that the ImportPath uniquely identifies a given copy of a package. 88 The Imports, Deps, TestImports, and XTestImports lists also contain these 89 expanded imports paths. See golang.org/s/go15vendor for more about vendoring. 90 91 The error information, if any, is 92 93 type PackageError struct { 94 ImportStack []string // shortest path from package named on command line to this one 95 Pos string // position of error (if present, file:line:col) 96 Err string // the error itself 97 } 98 99 The template function "join" calls strings.Join. 100 101 The template function "context" returns the build context, defined as: 102 103 type Context struct { 104 GOARCH string // target architecture 105 GOOS string // target operating system 106 GOROOT string // Go root 107 GOPATH string // Go path 108 CgoEnabled bool // whether cgo can be used 109 UseAllFiles bool // use files regardless of +build lines, file names 110 Compiler string // compiler to assume when computing target paths 111 BuildTags []string // build constraints to match in +build lines 112 ReleaseTags []string // releases the current release is compatible with 113 InstallSuffix string // suffix to use in the name of the install dir 114 } 115 116 For more information about the meaning of these fields see the documentation 117 for the go/build package's Context type. 118 119 The -json flag causes the package data to be printed in JSON format 120 instead of using the template format. 121 122 The -e flag changes the handling of erroneous packages, those that 123 cannot be found or are malformed. By default, the list command 124 prints an error to standard error for each erroneous package and 125 omits the packages from consideration during the usual printing. 126 With the -e flag, the list command never prints errors to standard 127 error and instead processes the erroneous packages with the usual 128 printing. Erroneous packages will have a non-empty ImportPath and 129 a non-nil Error field; other information may or may not be missing 130 (zeroed). 131 132 For more about build flags, see 'go help build'. 133 134 For more about specifying packages, see 'go help packages'. 135 `, 136 } 137 138 func init() { 139 cmdList.Run = runList // break init cycle 140 addBuildFlags(cmdList) 141 } 142 143 var listE = cmdList.Flag.Bool("e", false, "") 144 var listFmt = cmdList.Flag.String("f", "{{.ImportPath}}", "") 145 var listJson = cmdList.Flag.Bool("json", false, "") 146 var nl = []byte{'\n'} 147 148 func runList(cmd *Command, args []string) { 149 buildModeInit() 150 out := newTrackingWriter(os.Stdout) 151 defer out.w.Flush() 152 153 var do func(*Package) 154 if *listJson { 155 do = func(p *Package) { 156 b, err := json.MarshalIndent(p, "", "\t") 157 if err != nil { 158 out.Flush() 159 fatalf("%s", err) 160 } 161 out.Write(b) 162 out.Write(nl) 163 } 164 } else { 165 var cachedCtxt *Context 166 context := func() *Context { 167 if cachedCtxt == nil { 168 cachedCtxt = newContext(&buildContext) 169 } 170 return cachedCtxt 171 } 172 fm := template.FuncMap{ 173 "join": strings.Join, 174 "context": context, 175 } 176 tmpl, err := template.New("main").Funcs(fm).Parse(*listFmt) 177 if err != nil { 178 fatalf("%s", err) 179 } 180 do = func(p *Package) { 181 if err := tmpl.Execute(out, p); err != nil { 182 out.Flush() 183 fatalf("%s", err) 184 } 185 if out.NeedNL() { 186 out.Write(nl) 187 } 188 } 189 } 190 191 load := packages 192 if *listE { 193 load = packagesAndErrors 194 } 195 196 for _, pkg := range load(args) { 197 // Show vendor-expanded paths in listing 198 pkg.TestImports = pkg.vendored(pkg.TestImports) 199 pkg.XTestImports = pkg.vendored(pkg.XTestImports) 200 201 do(pkg) 202 } 203 } 204 205 // TrackingWriter tracks the last byte written on every write so 206 // we can avoid printing a newline if one was already written or 207 // if there is no output at all. 208 type TrackingWriter struct { 209 w *bufio.Writer 210 last byte 211 } 212 213 func newTrackingWriter(w io.Writer) *TrackingWriter { 214 return &TrackingWriter{ 215 w: bufio.NewWriter(w), 216 last: '\n', 217 } 218 } 219 220 func (t *TrackingWriter) Write(p []byte) (n int, err error) { 221 n, err = t.w.Write(p) 222 if n > 0 { 223 t.last = p[n-1] 224 } 225 return 226 } 227 228 func (t *TrackingWriter) Flush() { 229 t.w.Flush() 230 } 231 232 func (t *TrackingWriter) NeedNL() bool { 233 return t.last != '\n' 234 } 235
