FSLog

yes — Print a string until interrupted

Summary :

It prints the command line arguments, separated by spaces & followed by a newline, forever until it is killed. ‘yes’ can be used to feeds a continuous string of the character to another process and create dummy process for learning the process control.

Example:

$ yes — Prints `y’ followed by a newline until killed.

$ yes foobar — Prints foobar followed by a newline until killed.

$ yes `cat myfile` — Print myfile content until killed.

$ yes | fsck /dev/hda1 — Runs fsck non-interactively.

$ yes | rm -r mydir — Same effect as rm -rf mydir.

$ yes > /dev/null & — Dummy process. Redirects ‘y’ to null process and also runs in the background.

Read : man yes

yes, odoc, linux, gnu/linux

ps - Report Process Status
Summary :
ps gives a snapshot of the current processes. Lot of info, like CPU and MEM Usage, PID, UID, Status,…, about the present status of the process will be available in the ps output. ps can also be used as a debugging tool.
Example:

$ ps — Show all running in the current terminal.
$ ps -h — Same as above. But with-out header.
$ ps -ux — Show all processes owned by you.
$ ps -U sbharathi — Show all processes owned by sbharathi.
$ pc -C bash — Show all process with name bash.
$ ps -C syslogd -o pid= — Print PID of syslogd.
$ ps -aux — Show all processes including daemons (without tty) with username or UID.
$ ps -jx –sort=uid,-pid — All processes will list in ascending order of UID and each users process will sorted descending order.
$ ps -o start,time,etime -p 100 — Show the current status of the process with PID 100.
$ ps -e -o pid,state,cmd — Show all processes PID, State & Command (Custom output format -o ).
$ ps -ho “Process %a with PID %p is owned by %U” — Custom output.
$ ps -x -o pid,ruser=RealUser -o comm=Command -o stat=Status — Output with custom headers.

Read : man ps

ps, odoc, linux, gnu/linux

top — Display TOP Intensive processes

Summary :

TOP provides an ongoing look at processor activity in real time. TOP list the process, which is sorted based on the CPU usage of the each task on the system. It can also sort the tasks by memory usage & run time.

Examples :

$ top — List the most CPU-Intensive processes.
$ top -q — Runs with the highest possible priority.
$ top -d 6 — List will be updated every 6 Sec.
$ top -n 5 — Update the list for 5 times and then exit.
$ top -p 100 -p 200 — Monitor only process with PID 100 & 200. Maximum 20 processes can be monitored.
$ top -s — Run in secure mode (Disables the potentially dangerous interactive commands).
$ top -c — List the process with command line options instead of the command name only (default).
$ top -b -n 5 > myfile — Run in Batch mode & dump the output in myfile.

NOTE:

• Batch Mode is useful for sending output from top to other programs or to a file. It runs until it produces the number of iterations requested with the n option or until killed.
• TOP supports few interactive commands to change the output formats like changing update time and few actions like killing a process.

Read : man top

top, odoc, linux, gnu/linux,process

fmt — Simple optimal text ForMatTer

Summary :

fmt reads from the specified file arguments or stdin, and writes to stdout.

Examples :

$ fmt myfile — Format myfile and max line length is 75.

$ fmt f1 f2 — Format f1 f2 and max line length is 75.

$ fmt -w 60 f1 f2 — Same as above but max line length is 60.

$ fmt -s myfile — Don’t split the small line. Useful if your file contains some sample program codes.

$ fmt -u myfile — Uniform spacing. One space between words. Two space between sentences.

$ fmt -p BB myfile — Only lines beginning with BB will be formatted.

$ fmt -t myfile — Paragraph indentation will be preserved.

Note: By default, blank lines, spaces between words, and indentation are preserved in the output; successive input lines with different indentation are not joined; tabs are expanded on input and introduced on output.

Read : man fmt

odoc, fmt, linux, gnu/linux