InterviewSolution
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How Do You Change File Access Permissions? |
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Answer» Every file has following attributes: owner's USER ID ( 16 bit integer ) owner's group ID ( 16 bit integer ) File access mode word 'r w x -r w x- r w x' (user permission-group permission-others permission) r-READ, w-write, x-execute To change the access mode, we use chmod(filename,mode). Example 1: To change mode of myfile to 'rw-rw-r–' (ie. read, write permission for user - read,write permission for group - only read permission for others) we give the args as: chmod(myfile,0664) . Each operation is REPRESENTED by DISCRETE values 'r' is 4 'w' is 2 'x' is 1 Therefore, for 'rw' the value is 6(4+2). Example 2: To change mode of myfile to 'rwxr–r–' we give the args as: chmod(myfile,0744). Every file has following attributes: owner's user ID ( 16 bit integer ) owner's group ID ( 16 bit integer ) File access mode word 'r w x -r w x- r w x' (user permission-group permission-others permission) r-read, w-write, x-execute To change the access mode, we use chmod(filename,mode). Example 1: To change mode of myfile to 'rw-rw-r–' (ie. read, write permission for user - read,write permission for group - only read permission for others) we give the args as: chmod(myfile,0664) . Each operation is represented by discrete values 'r' is 4 'w' is 2 'x' is 1 Therefore, for 'rw' the value is 6(4+2). Example 2: To change mode of myfile to 'rwxr–r–' we give the args as: chmod(myfile,0744). |
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