ref: d848aee0239e478399eb4dc44501803e125f1957
dir: /sys/man/3/shr/
.TH SHR 3 .SH NAME shr \- global mountpoints .SH SYNOPSIS .nf .B bind '#σ' /shr .BI #σ/ share1 .BI #σc/ share1/service1 .BI #σc/ share1/service2 ... .fi .SH DESCRIPTION The .I shr device provides global mountpoints in the form of share directories where .IR 9P services can be mounted. Effectively, it is a global mountpoint registry that is separate from private namespaces. .PP The .I shr device exports a mount tree and a control tree. The directories in the mount tree .BI #σ are the share mountpoints themselves, while the directories in .BI #σc contain the service files of the share. .PP To create a new share, create the directory .B #σc/myshare To mount a service in that share, create the file .B #σc/myshare/myserv and then write a text string (suitable for .IR strtoul ; see .IR atof (2)) giving the file descriptor number of an open .I 9P service. Any process with the proper permission may then access .B #σ/myshare on the mount tree. .PP The service file can be reopened and passed to .IR mount (see .IR bind (2)) or added to another share. .PP Multiple services can be mounted under a share forming a union directory. New services get mounted before old ones. Removing the service file unmounts the service from the share. .PP Creating shares and mounts requires read-write access in the share directory. The special user .B none is prohibited from these operations. .SH EXAMPLES To mount a 9p service from .IR srv (3) to the shr device .IP .EX mkdir '#σc'/myshare echo 3 > '#σc'/myshare/myserv <>[3]/srv/myserv .EE .SH SOURCE .B /sys/src/9/port/devshr.c .SH HISTORY .I Shr first appeared in 9front (July, 2011).