Search results
Results from the WOW.Com Content Network
time — Run command line and report real, user, and system time elapsed in seconds. timeout — Run command line as a child process, sending child a signal if the command doesn't exit soon enough. top — Show process activity in real time. touch — Update the access and modification times of each FILE to the current time. true — Return zero.
Many command line programs, such as cURL [1] or Bash [2],can be set to verbose mode by using a flag, such as -v or --verbose. References
The Unix command su, which stands for 'substitute user' [1] [2] (or historically 'superuser' [3] [4]), is used by a computer user to execute commands with the privileges of another user account. When executed it invokes a shell without changing the current working directory or the user environment.
In Linux, if the script was executed by a regular user, the shell would attempt to execute the command rm -rf / as a regular user, and the command would fail. However, if the script was executed by the root user, then the command would likely succeed and the filesystem would be erased. It is recommended to use sudo on a per-command basis instead.
After authentication, and if the configuration file permits the user access, the system invokes the requested command. sudo retains the user's invocation rights through a grace period (typically 5 minutes) per pseudo terminal, allowing the user to execute several successive commands as the requested user without having to provide a password again.
The Linux console is a system console internal to the Linux kernel. A system console is the device which receives all kernel messages and warnings and which allows logins in single user mode. [1] The Linux console provides a way for the kernel and other processes to send text output to the user, and to receive text input from the user.
A chmod command first appeared in AT&T Unix version 1, along with the chmod system call. As systems grew in number and types of users, access-control lists [3] were added to many file systems in addition to these most basic modes to increase flexibility. The version of chmod bundled in GNU coreutils was written by David MacKenzie and Jim ...
The test command in Unix evaluates the expression parameter. In most recent shell implementations, it is a shell builtin, even though the external version still exists.In the second form of the command, the [ ] (brackets) must be surrounded by blank spaces (this is because [is a program and POSIX compatible shells require a space between the program name and its arguments).