Add man page and fix typo for update command

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>

man/runc-update.8.md

@@ -0,0 +1,44 @@
+# NAME
+   runc update - update container resource constraints
+
+# SYNOPSIS
+   runc update [command options] <container-id>
+
+# DESCRIPTION
+   The data can be read from a file or the standard input, the
+accepted format is as follow (unchanged values can be omitted):
+
+   {
+     "memory": {
+       "limit": 0,
+       "reservation": 0,
+       "swap": 0,
+       "kernel": 0
+     },
+     "cpu": {
+       "shares": 0,
+       "quota": 0,
+       "period": 0,
+       "cpus": "",
+       "mems": ""
+     },
+     "blockIO": {
+       "blkioWeight": 0
+     },
+   }
+
+Note: if data is to be read from a file or the standard input, all
+other options are ignored.
+
+# OPTIONS
+   --resources, -r         path to the file containing the resources to update or '-' to read from the standard input.
+   --blkio-weight "0"      Specifies per cgroup weight, range is from 10 to 1000.
+   --cpu-period            CPU period to be used for hardcapping (in usecs). 0 to use system default.
+   --cpu-quota             CPU hardcap limit (in usecs). Allowed cpu time in a given period.
+   --cpu-share             CPU shares (relative weight vs. other containers)
+   --cpuset-cpus           CPU(s) to use
+   --cpuset-mems           Memory node(s) to use
+   --kernel-memory         Kernel memory limit (in bytes) for tcp buffer
+   --memory                Memory limit (in bytes)
+   --memory-reservation    Memory reservation or soft_limit (in bytes)
+   --memory-swap           Total memory usage (memory + swap); set `-1` to enable unlimited swap

update.go

@@ -18,7 +18,7 @@ func u16Ptr(i uint16) *uint16 { return &i }
 var updateCommand = cli.Command{
 	Name:      "update",
 	Usage:     "update container resource constraints",
-	ArgsUsage: `<container-id> <ps options>`,
+	ArgsUsage: `<container-id>`,
 	Flags: []cli.Flag{
 		cli.StringFlag{
 			Name:  "resources, r",
@@ -46,7 +46,7 @@ The accepted format is as follow (unchanged values can be omitted):
   },
 }
 
-Note: if data is to be read from a file or the standard output all
+Note: if data is to be read from a file or the standard input, all
 other options are ignored.
 `,
 		},