chemod
Change file extended mode bits (non-POSIX)
Syntax:
chemod [-Rv] [-s | -c mode_bits] path
Runs on:
QNX OS
Options:
- -c mode_bits
- Clear the bits specified by mode_bits.
For more information, see
Extended mode bits.
- -R
- Recursively act on every file and directory under the specified path. Depending on the value provided, -s or -c, this option causes chemod to set or clear the bits on the given path and all files and directories under path.
- -s mode_bits
- Set the bits specified by mode_bits.
For more information, see
Extended mode bits.
- -v
- Enable verbosity. Enables chemod to display the changes that are being performed.
- path
- Path to modify.
Description:
The chemod utility displays or modifies the extended mode bits of the specified path. The mode_bits variable is a string of characters indicating which bits should be modified. Extended mode bits are currently only supported on the Power-Safe filesystem.
If neither the -c nor the -s option is given, chemod displays the mode_bits value for the given path. If multiple -c or -s options are given, the last one takes effect.
Extended mode bits
The mode_bits value can be any combination of the following characters:
- a
- This file is affected by the artificial free space limit (alimit=) filesystem value. For more information on how alimit can be used, see fs-qnx6.so.
- i
- All file modifications are in-place, which disables the Copy-on-Write semantics of the Power-Safe filesystem, for the specified path. This implies a loss of power-loss resilience in the file data.
Examples:
Marks myfile as being affected by the artificial free space limit (alimit=) filesystem value:
chemod -s a myfile
Removes the artificial free space limit (alimit=) from myfile:
chemod -c a myfile
Marks myfile as having the Copy-on-Write semantics of the Power-Safe filesystem disabled, for the specified path. This implies a loss of power-loss resiliency in the file data:
chemod -s i myfile
Marks myfile as having the Copy-on-Write semantics of the Power-Safe filesystem enabled, for the specified path. This allows for power-loss resiliency in the file data:
chemod -c i myfile
Marks myfile as being both affected by the artificial free space limit (alimit=) filesystem value and having the Copy-on-Write semantics of the Power-Safe filesystem disabled, for the specified path:
chemod -s ai myfile