Since Apache Ant 1.7.1


Set the length of one or more files, as the truncate Unix function or GNU utility. In addition to working with a single file, this Task can also work on resources and resource collections.


Attribute Description Required
file The name of the file. Unless a nested resource collection element has been specified
length Specifies the new file length (in bytes) to set. The following suffixes are supported:
  • K : Kilobytes (1024 bytes)
  • M : Megabytes (1024 K)
  • G : Gigabytes (1024 M)
  • T : Terabytes (1024 G)
  • P : Petabytes (1024 T)
At most one of these; omitting both implies length=0
adjust Specifies the number of bytes (and positive/negative direction) by which to adjust file lengths. The same suffixes are supported for this attribute as for the length attribute.
create Whether to create nonexistent files. No; default true
mkdirs Whether to create nonexistent parent directories when creating new files. No; default false

Parameters specified as nested elements

any resource collection

You can use any number of nested resource collection elements to define the resources for this task and refer to resources defined elsewhere. Note: resources passed to this task are expected to be filesystem-based.


Set the length of file foo to zero.

<truncate file="foo"/>

Set the length of file foo to 1 kilobyte (1024 bytes).

<truncate file="foo" length="1K"/>

Adjust the length of file foo upward by 1 kilobyte.

<truncate file="foo" adjust="1K"/>

Adjust the length of file foo downward by 1 megabyte.

<truncate file="foo" adjust="-1M"/>