ITM 12 – Linux Essentials Blog Post #2


If you issue the ls -l for a certain file, there will be 10 characters like so: -rw-r–r–. The characters from 2-4 are the permissions for the file owner, 5-7 are for the group that owns said file, and 8-10 are for the “others” or everybody that doesn’t fit into the first two categories. 1 is for the type of file being shown. For the type of file there are 7 different options.

indicates a normal file with text
d indicates a file with names of other files and links of them
l indicates a symbolic link, name that refers to another file
b indicates a block file. Shows a “block hardware device” in which data is read in blocks
c indicates a character file. Presents a “character hardware device” in which data is read in individual bytes.
p indicates a pipe file. Similar to the pipe character, the output of a process is continued and imputed into another process.
s indicates a socket file. Lets two processes correspond with each other. They can both send and receive information.


For the permissions there are only 3 characters (r,w,and x). They take that same order in each of the 3 segments and if one is not applied the space is blank -.


r represents the permission to read. Info can be viewed/copied.
w represents the permission to write. File can be “written to” and save the change. Works best if r is enabled
x represents the permission to execute. A file could now be carried out as a operation/process.


Permission are very important to managing information and who can do what to certain files.

Leave a Reply

Your email address will not be published. Required fields are marked *