touch 命令

常用示例

说明

touch updates file access and modification timestamps. If the file doesn't exist, touch creates an empty file (unless -c or -h is specified). Common uses include creating empty files, updating timestamps to trigger make rebuilds, and setting specific times for testing or archival purposes. Time can be specified in several formats: -t for precise timestamps, -d for human-readable strings ("yesterday", "2 hours ago"), or -r to copy times from another file. Without -a or -m, both access time (atime) and modification time (mtime) are updated. Change time (ctime) is always updated by the kernel when timestamps change.

参数

-a

Change only access time

-m

Change only modification time

-c, --no-create

Do not create file if it doesn't exist

-d _string_, --date=_string_

Parse string and use instead of current time

-r _file_, --reference=_file_

Use times from reference file

-t _stamp_

Use timestamp [CCYY]MMDDhhmm.ss instead of current time

-h, --no-dereference

Affect symbolic link instead of referenced file

--time=_WORD_

Change the specified time: _access_, _atime_, _use_ are equivalent to -a; _modify_, _mtime_ are equivalent to -m

-f

Ignored; provided for compatibility with BSD versions of touch