lookup.go

Documentation: os/user

		 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 user
		 6  
		 7  import "sync"
		 8  
		 9  // Current returns the current user.
		10  //
		11  // The first call will cache the current user information.
		12  // Subsequent calls will return the cached value and will not reflect
		13  // changes to the current user.
		14  func Current() (*User, error) {
		15  	cache.Do(func() { cache.u, cache.err = current() })
		16  	if cache.err != nil {
		17  		return nil, cache.err
		18  	}
		19  	u := *cache.u // copy
		20  	return &u, nil
		21  }
		22  
		23  // cache of the current user
		24  var cache struct {
		25  	sync.Once
		26  	u	 *User
		27  	err error
		28  }
		29  
		30  // Lookup looks up a user by username. If the user cannot be found, the
		31  // returned error is of type UnknownUserError.
		32  func Lookup(username string) (*User, error) {
		33  	if u, err := Current(); err == nil && u.Username == username {
		34  		return u, err
		35  	}
		36  	return lookupUser(username)
		37  }
		38  
		39  // LookupId looks up a user by userid. If the user cannot be found, the
		40  // returned error is of type UnknownUserIdError.
		41  func LookupId(uid string) (*User, error) {
		42  	if u, err := Current(); err == nil && u.Uid == uid {
		43  		return u, err
		44  	}
		45  	return lookupUserId(uid)
		46  }
		47  
		48  // LookupGroup looks up a group by name. If the group cannot be found, the
		49  // returned error is of type UnknownGroupError.
		50  func LookupGroup(name string) (*Group, error) {
		51  	return lookupGroup(name)
		52  }
		53  
		54  // LookupGroupId looks up a group by groupid. If the group cannot be found, the
		55  // returned error is of type UnknownGroupIdError.
		56  func LookupGroupId(gid string) (*Group, error) {
		57  	return lookupGroupId(gid)
		58  }
		59  
		60  // GroupIds returns the list of group IDs that the user is a member of.
		61  func (u *User) GroupIds() ([]string, error) {
		62  	return listGroups(u)
		63  }
		64
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