awk - 如何使用 awk 提取特定 VM 和组的 UUID？

Question

我正在使用 vboxmanage list -l vms，我想通过提供 Name 和 Groups 值来提取特定机器的 UUID .

Name:                        vm2
Groups:                      /C05Lab1
Guest OS:                    Oracle (64-bit)
UUID:                        54c233e8-3d5b-46bb-9a21-a8946ffa7d76
Config file:                 C:\Users\Bianca\VirtualBox VMs\C05Lab1\vm2\vm2.vbox
Snapshot folder:             C:\Users\Bianca\VirtualBox VMs\C05Lab1\vm2\Snapshots
Log folder:                  C:\Users\Bianca\VirtualBox VMs\C05Lab1\vm2\Logs
Hardware UUID:               54c233e8-3d5b-46bb-9a21-a8946ffa7d76

我必须:

vboxmanage list -l vms | awk '$1=="UUID:"{uid=$2} /Name: *vm2/{print uid}'

它至少列出了一个 uuid，但不是正确的(它在它之前打印机器的 uuid)而且我不知道如何检查 Groups 值，因为它以/

Answer 1

使用您展示的示例，请尝试遵循 awk 代码。

vboxmanage list -l vms | 
awk -v name="vm2" -v group="C05Lab1" '
/^Name:/{
  foundName=foundGroup=""
  if($2==name){ foundName=1 }
  next
}
/^Groups:/ && $2==group{
  foundGroup=1
  next
}
/^UUID:/ && foundName && foundGroup{
  print
  foundName=foundGroup=""
}'

说明:在此处添加详细说明。

vboxmanage list -l vms |               ##Running command vboxmanage list -l vms and sending its Output to awk as an input.
awk -v name="vm2" -v group="C05Lab1" ' ##Starting awk command from here and setting name to vm2 and group to C05Lab1 here.
/^Name:/{                              ##Checking condition if line starts with Name: then do following.
  foundName=foundGroup=""              ##Nullifying foundName and foundGroup here.
  if($2==name){ foundName=1 }          ##Checking condition if 2nd field is name then set foundName to 1 here.
  next                                 ##next will skip all further statements from here.
}
/^Groups:/ && $2==group{               ##Checking condition if line starts from Groups: and 2nd field is group then do following.
  foundGroup=1                         ##Setting foundGroup to 1 here.
  next                                 ##next will skip all further statements from here.
}
/^UUID:/ && foundName && foundGroup{   ##Checking condition if line starts from UUID: and foundName and foundGroup are set then do following.
  print                                ##Printing currnet line here.
  foundName=foundGroup=""              ##Nullifying foundName and foundGroup here.
}'

---

由 Ed Morton 编辑以展示注释代码的另一种方法，即注释说为什么我们正在做某事而不是什么我们正在做:

vboxmanage list -l vms |
awk -v name="vm2" -v group="C05Lab1" ' # Set variables to contain the Name: and Groups: values we want to find in the input
/^Name:/{                              # We assume that every record starts with Name: and so we clear the
  foundName=foundGroup=""              # foundName and foundGroup flags here so that when we hit the UUID:
                                       # line later they arent still set from reading the previous record.
  if($2==name){ foundName=1 }          # If the current value of the Name: matches the target value stored in
                                       # our "name" variable then set the flag to indicate that so when we test
                                       # it on our UUID: line we know we found the target name.
  next
}
/^Groups:/ && $2==group{               # If the current value of the Group: matches the target value stored in
  foundGroup=1                         # our "group" variable then set the flag to indicate that so when we test
                                       # it on our UUID: line we know we found the target group.
  next
}
/^UUID:/ && foundName && foundGroup{   # Were on the UUID: line from the input so if we had previously found
  print                                # our target "name" and "group" as indicated by the 2 flags we set earlier
                                       # then we output the current line which contains the UUID.
  foundName=foundGroup=""              # Clear foundName and foundGroup flags here to ensure that when we hit the UUID:
                                       # line for the next record they arent still set from reading the current record
}'