How to run the hash command to calculate the MD5 hash or the CRC-64 value of a local file - Object Storage Service

This topic describes how to run the hash command to calculate the MD5 hash or the CRC-64 value of a local file.

Usage notes

To calculate the hash of a local file, you must have the oss:GetObject permission. For more information, see Attach a custom policy to a RAM user.
By default, the object hash calculated by the server is used, which is the CRC-64 value or the Content-MD5 value obtained by calling the headobject operation. If the hash does not exist, download the object and calculate the hash.

Command syntax

ossutil hash md5|crc64 source [flags]

Parameter	Type	Description
--base64	/	Specifies whether base64-encode the object hash.
-d, --dirs	/	Specifies that the objects and subdirectories in the current directory are returned.
--download	/	Specifies whether to download the object for hash calculation.
--encoding-type	string	The encoding method used to encode the destination object name. Valid value: url.
--end-with	string	Specifies that objects whose names are alphabetically before or the same as the value of the --end-with parameter are returned.
--exclude	stringArray	The exclusion rule for the path or object name.
--exclude-from	stringArray	Specifies that the exclusion rule is read from the rules file.
--files-from	stringArray	Specifies that the object names are read from the rules file, and empty lines or comment lines are ignored.
--files-from-raw	stringArray	Specifies that the object names are read from the rules file.
--filter	stringArray	The filter rule for the path or object name.
--filter-from	stringArray	Specifies that the filter rule for the path or object name is read from the rules file.
-f, --force	/	Specifies that the command is forcibly run without a prompt for confirmation.
--include	stringArray	The inclusion rule for the path or object name.
--include-from	stringArray	Specifies that the inclusion rule is read from the rules file.
--limited-num	int	The maximum number of results to return.
--list-objects	/	Specifies that the ListObjects operation is called to list objects.
--max-age	Duration	Specifies that the objects whose last modified time is earlier than the value of the --max-age parameter are not transferred. The default unit is seconds. The unit can be milliseconds, seconds, minutes, hours, days, weeks, months, or years. By default, this parameter is left empty.
--max-mtime	Time	Specifies that the objects whose last modified time is later than the value of the --max-mtime parameter are not transferred. The value is in UTC. By default, this parameter is left empty.
--max-size	SizeSuffix	Specifies the maximum size of the object that can be transferred. The default unit is bytes. The unit of object size can be bytes, KiB, MiB, GiB, TiB, or PiB. Note: 1 KiB = 1024 bytes.
--metadata-exclude	stringArray	The exclusion rule for object metadata.
--metadata-filter	stringArray	The filter rule for object metadata.
--metadata-filter-from	stringArray	Specifies that the filter rule for object metadata is read from the rules file.
--metadata-include	stringArray	The inclusion rule for object metadata.
--min-age	Duration	Specifies that the objects whose last modified time is later than the value of the --min-age parameter are not transferred. The default unit is seconds. The unit can be milliseconds, seconds, minutes, hours, days, weeks, months, or years. By default, this parameter is left empty.
--min-mtime	Time	Specifies that the objects whose last modified time is earlier than the value of the --min-mtime parameter are not transferred. The value is in UTC. By default, this parameter is left empty.
--min-size	SizeSuffix	Specifies the minimum size of the object that can be transferred. The default unit is bytes. The unit of object size can be bytes, KiB, MiB, GiB, TiB, or PiB. Note: 1 KiB = 1024 bytes.
--page-size	int	The maximum number of objects that can be returned. Default value: 1000. Valid values: 1 to 1000.
-r, --recursive	/	Specifies that the command is recursively run on objects. If this parameter is specified, the command takes effect on all objects that meet the conditions in the bucket. Otherwise, the command takes effect on only the objects in the specified path.
--request-payer	string	Specifies the payer of the request. If pay-by-requester is enabled for the bucket, set this parameter to requester.
--start-after	string	Specifies that objects whose names are alphabetically after the value of the --start-after parameter are returned.

Note

For more information, see Command-line options.

Examples

Calculate the hash of a local file named example.txt:
```
ossutil hash md5 example.txt
```
Calculate and base64-encode the hash of a local file named example.txt:
```
 ossutil hash md5 example.txt --base64
```
Calculate the CRC-64 of a local file named example.txt:
```
ossutil hash crc64 example.txt
```
Calculate the hash of local files in a directory named folder:
```
ossutil hash md5 folder/ -r
```
Calculate and base64-encode the hash of local files in a directory named folder:
```
ossutil hash md5 folder/ -r --base64
```
Calculate the CRC-64 of local files in a directory named folder:
```
ossutil hash crc64 folder/ -r
```
Calculate the hash of an object named example.txt in a bucket namedexamplebucket:
```
ossutil hash md5 oss://examplebucket/example.txt
```