forked from crystal-lang/crystal
/
user.cr
49 lines (37 loc) · 1.46 KB
/
user.cr
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require "c/pwd"
module Crystal::System::User
private GETPW_R_SIZE_MAX = 1024 * 16
private def from_struct(pwd)
user = String.new(pwd.pw_gecos).split(",").first
new(String.new(pwd.pw_name), pwd.pw_uid.to_s, pwd.pw_gid.to_s, user, String.new(pwd.pw_dir), String.new(pwd.pw_shell))
end
private def from_username?(username : String)
username.check_no_null_byte
pwd = uninitialized LibC::Passwd
pwd_pointer = pointerof(pwd)
initial_buf = uninitialized UInt8[1024]
buf = initial_buf.to_slice
ret = LibC.getpwnam_r(username, pwd_pointer, buf, buf.size, pointerof(pwd_pointer))
while ret == LibC::ERANGE && buf.size < GETPW_R_SIZE_MAX
buf = Bytes.new(buf.size * 2)
ret = LibC.getpwnam_r(username, pwd_pointer, buf, buf.size, pointerof(pwd_pointer))
end
raise Errno.new("getpwnam_r") if ret != 0
from_struct(pwd) if pwd_pointer
end
private def from_id?(id : String)
id = id.to_u32?
return unless id
pwd = uninitialized LibC::Passwd
pwd_pointer = pointerof(pwd)
initial_buf = uninitialized UInt8[1024]
buf = initial_buf.to_slice
ret = LibC.getpwuid_r(id, pwd_pointer, buf, buf.size, pointerof(pwd_pointer))
while ret == LibC::ERANGE && buf.size < GETPW_R_SIZE_MAX
buf = Bytes.new(buf.size * 2)
ret = LibC.getpwuid_r(id, pwd_pointer, buf, buf.size, pointerof(pwd_pointer))
end
raise Errno.new("getpwuid_r") if ret != 0
from_struct(pwd) if pwd_pointer
end
end