Syslog

1.0 Syslog

Syslog is a protocol for conveying event notification messages.

Syslog was first developed by Eric Allman for logging as a part of the Sendmail project in the 1980s. It soon became a de-facto standard for logging on Unix-like systems.… Read more

tmpfs in Linux

tmpfs

1.0 tmpfs

tmpfs is a filesystem that resides in the main memory of a Linux system. In the case of disk files, a file is first fetched into the kernel pagecache and the delivered to the requesting process. The fetch part is not there in the case of tmpfs as the files are created and updated directly in kernel caches.… Read more

tr Command in Linux

1.0 tr

The tr command is a filter which reads the standard input, translates or deletes characters and writes on its standard output. The tr command syntax is,

tr [OPTION]... SET1 [SET2]

tr transliterates characters from SET1 into corresponding characters of SET2 in input and writes resulting text on the standard output.… Read more

Sort command in Linux

1.0 Sort

The sort command is for sorting lines in text files. For example, if we have a file names, we can sort it with the sort command,

$ cat names
John Doe
Jane Doe
John Roe
Richard Roe
Tommy Atkins
Max Mustermann
Erika Mustermann
Joe Bloggs
$
$ sort names
Erika Mustermann
Jane Doe
Joe Bloggs
John Doe
John Roe
Max Mustermann
Richard Roe
Tommy Atkins

The words in the input lines are fields, which are numbered 1 onwards.… Read more

Awk Tutorial

1.0 awk

awk is a filter which takes the input and gives output after matching desired patterns and doing processing linked to matched patterns. awk is well suited for processing voluminous raw text data and producing statistical reports from it.

awk is named after the first character of the names of its designers, Al Aho, Peter Weinberger and Brian Kernighan, who developed it for Unix systems in the 1970s.… Read more