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SUSE LINUX Documentation - Index of

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u<br />

g<br />

o<br />

User<br />

Group<br />

Others<br />

For access, grant access with + and deny it with -.<br />

The access type is controlled by the following options:<br />

r<br />

w<br />

x<br />

s<br />

Read<br />

Write<br />

Execute—executing files or changing to the directory<br />

Setuid bit—the application or program is started as if it were started by the<br />

owner <strong>of</strong> the file<br />

As an alternative, a numeric code can be used. The four digits <strong>of</strong> this code are<br />

composed <strong>of</strong> the sum <strong>of</strong> the values 4, 2, and 1—the decimal result <strong>of</strong> a binary mask.<br />

The first digit sets the set user ID (SUID) (4), the set group ID (2), and the sticky<br />

(1) bits. The second digit defines the permissions <strong>of</strong> the owner <strong>of</strong> the file. The third<br />

digit defines the permissions <strong>of</strong> the group members and the last digit sets the permissions<br />

for all other users. The read permission is set with 4, the write permission<br />

with 2, and the permission for executing a file is set with 1. The owner <strong>of</strong> a file<br />

would usually receive a 6 or a 7 for executable files.<br />

gzip [parameters] files<br />

This program compresses the contents <strong>of</strong> files using complex mathematical algorithms.<br />

Files compressed in this way are given the extension .gz and need to be<br />

uncompressed before they can be used. To compress several files or even entire<br />

directories, use the tar command.<br />

Working with the Shell 109

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