1 // Copyright 2015 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 //go:generate ./mkalldocs.sh 6 7 package main 8 9 var cmdDoc = &Command{ 10 Run: runDoc, 11 UsageLine: "doc [-u] [-c] [package|[package.]symbol[.method]]", 12 CustomFlags: true, 13 Short: "show documentation for package or symbol", 14 Long: ` 15 Doc prints the documentation comments associated with the item identified by its 16 arguments (a package, const, func, type, var, or method) followed by a one-line 17 summary of each of the first-level items "under" that item (package-level 18 declarations for a package, methods for a type, etc.). 19 20 Doc accepts zero, one, or two arguments. 21 22 Given no arguments, that is, when run as 23 24 go doc 25 26 it prints the package documentation for the package in the current directory. 27 If the package is a command (package main), the exported symbols of the package 28 are elided from the presentation unless the -cmd flag is provided. 29 30 When run with one argument, the argument is treated as a Go-syntax-like 31 representation of the item to be documented. What the argument selects depends 32 on what is installed in GOROOT and GOPATH, as well as the form of the argument, 33 which is schematically one of these: 34 35 go doc <pkg> 36 go doc <sym>[.<method>] 37 go doc [<pkg>.]<sym>[.<method>] 38 go doc [<pkg>.][<sym>.]<method> 39 40 The first item in this list matched by the argument is the one whose documentation 41 is printed. (See the examples below.) However, if the argument starts with a capital 42 letter it is assumed to identify a symbol or method in the current directory. 43 44 For packages, the order of scanning is determined lexically in breadth-first order. 45 That is, the package presented is the one that matches the search and is nearest 46 the root and lexically first at its level of the hierarchy. The GOROOT tree is 47 always scanned in its entirety before GOPATH. 48 49 If there is no package specified or matched, the package in the current 50 directory is selected, so "go doc Foo" shows the documentation for symbol Foo in 51 the current package. 52 53 The package path must be either a qualified path or a proper suffix of a 54 path. The go tool's usual package mechanism does not apply: package path 55 elements like . and ... are not implemented by go doc. 56 57 When run with two arguments, the first must be a full package path (not just a 58 suffix), and the second is a symbol or symbol and method; this is similar to the 59 syntax accepted by godoc: 60 61 go doc <pkg> <sym>[.<method>] 62 63 In all forms, when matching symbols, lower-case letters in the argument match 64 either case but upper-case letters match exactly. This means that there may be 65 multiple matches of a lower-case argument in a package if different symbols have 66 different cases. If this occurs, documentation for all matches is printed. 67 68 Examples: 69 go doc 70 Show documentation for current package. 71 go doc Foo 72 Show documentation for Foo in the current package. 73 (Foo starts with a capital letter so it cannot match 74 a package path.) 75 go doc encoding/json 76 Show documentation for the encoding/json package. 77 go doc json 78 Shorthand for encoding/json. 79 go doc json.Number (or go doc json.number) 80 Show documentation and method summary for json.Number. 81 go doc json.Number.Int64 (or go doc json.number.int64) 82 Show documentation for json.Number's Int64 method. 83 go doc cmd/doc 84 Show package docs for the doc command. 85 go doc -cmd cmd/doc 86 Show package docs and exported symbols within the doc command. 87 go doc template.new 88 Show documentation for html/template's New function. 89 (html/template is lexically before text/template) 90 go doc text/template.new # One argument 91 Show documentation for text/template's New function. 92 go doc text/template new # Two arguments 93 Show documentation for text/template's New function. 94 95 At least in the current tree, these invocations all print the 96 documentation for json.Decoder's Decode method: 97 98 go doc json.Decoder.Decode 99 go doc json.decoder.decode 100 go doc json.decode 101 cd go/src/encoding/json; go doc decode 102 103 Flags: 104 -c 105 Respect case when matching symbols. 106 -cmd 107 Treat a command (package main) like a regular package. 108 Otherwise package main's exported symbols are hidden 109 when showing the package's top-level documentation. 110 -u 111 Show documentation for unexported as well as exported 112 symbols and methods. 113 `, 114 } 115 116 func runDoc(cmd *Command, args []string) { 117 run(buildToolExec, tool("doc"), args) 118 } 119
