(command.CommandList children: [ (command.ShAssignment pairs: [ (assign_pair lhs: (sh_lhs_expr.Name name:TMP) op: assign_op.Equal rhs: { (command_sub left_token: <Id.Left_Backtick '`'> child: (C {<mktemp>} {<-d>} {<'/tmp/mtree.XXXXXX'>}) ) } spids: [19] ) ] ) (C {<mkdir>} {<-p>} {(${ Id.VSub_Name TMP) <'/mr'>} {(${ Id.VSub_Name TMP) <'/mr/optional-dir'>} {(${ Id.VSub_Name TMP) <'/mr/some-dir'>} ) (C {<touch>} {(${ Id.VSub_Name TMP) <'/mr/optional-file'>} {(${ Id.VSub_Name TMP) <'/mr/some-file'>}) (command.Simple words: [{<mtree>} {<-c>} {<-p>} {(${ Id.VSub_Name TMP) <'/mr'>}] redirects: [ (redir op: <Id.Redir_Great '>'> loc: (redir_loc.Fd fd:1) arg: {(${ Id.VSub_Name TMP) <'/_'>} ) ] do_fork: T ) (C {<rm>} {<-rf>} {(${ Id.VSub_Name TMP) <'/mr/optional-file'>} {(${ Id.VSub_Name TMP) <'/mr/optional-dir'>} ) (command.Simple words: [{<mtree>} {<-p>} {(${ Id.VSub_Name TMP) <'/mr'>} {<-K>} {<optional>}] redirects: [ (redir op: <Id.Redir_Less '<'> loc: (redir_loc.Fd fd:0) arg: {(${ Id.VSub_Name TMP) <'/_'>} ) (redir op:<Id.Redir_Great '>'> loc:(redir_loc.Fd fd:1) arg:{<'/dev/null'>}) ] do_fork: T ) (command.ShAssignment pairs: [ (assign_pair lhs: (sh_lhs_expr.Name name:res) op: assign_op.Equal rhs: {($ Id.VSub_QMark '$?')} spids: [119] ) ] ) (command.If arms: [ (if_arm cond: (condition.Shell commands: [ (command.Sentence child: (C {<Id.Lit_LBracket '['>} {($ Id.VSub_DollarName '$res')} {<-ne>} {<0>} {<Id.Lit_RBracket ']'>} ) terminator: <Id.Op_Semi _> ) ] ) action: [ (command.Simple words: [{<echo>} {(DQ <'ERROR \'optional\' keyword failed'>)}] redirects: [(redir op:<Id.Redir_GreatAnd '1>&'> loc:(redir_loc.Fd fd:1) arg:{<2>})] do_fork: T ) (C {<rm>} {<-rf>} {(${ Id.VSub_Name TMP)}) (command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<1>}) ] spids: [123 137] ) ] ) (C {<rm>} {<-rf>} {(${ Id.VSub_Name TMP)}) (command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<0>}) ] )