ulimit, Bash built-in command, provides control over the resources
(Virtual Mem, Max no .of process, Core file size, …) available to
processes started by the shell.
For example, If max no. of user process is set to 5, then that
particular user can’t run more then 5 process.
$ ulimit -n — Show max open files.
groupmod — Modify a group
Summary
The groupmod command modifies the system account files to reflect the
changes that are specified on the command line.
Example
# groupmod -g 600 mygrp — Change the mygrp Group ID to 600.
# groupmod -n mygrp1 mygrp — Change the mygrp name to mygrp1.
Group informations are stored in /etc/group files.
The main function is the first program that gets executed when the program starts, what else is so important about this? good, there are some more to learn about this main function lets start.
the prototype
int main()
or
int main(int argc, char *argv[])
or
int main(int argc, char **argv)
or
int main(int argc, char **argv, char *env[])
or
int main(int argc, char **argv, char **env)
Note: char ** and char *[] are the same
Is the last two prototypes valid? yes, it is valid. We will discuss later