The /etc/security/limits file is an ASCII file that contains stanzas that specify the process resource limits for each user. These limits are set by individual attributes within a stanza.
Each stanza is identified by a user name followed by a colon and contains attributes in the Attribute=Value form. Each attribute is ended by a new-line character, and each stanza is ended by an additional new-line character. If you do not define an attribute for a user, the system applies default values. The default attributes, and attributes for the user smith, are shown in Figure below
Figure : Contents of /etc/security/limits file
When you create a user with the mkuser command, the system adds a stanza for the user to the /etc/security/limits file. Once the stanza exists, you can use the chuser command to change the user's limits. To display the current limits for a