![]() ![]() Other programming languages, like Python and Perl, use compilers or interpreters that are written in C.Ĭ has changed over the years and is still a common language to use in lower level programs, like kernels. Also databases such as Oracle Database, MySQL, MS SQL Server, and PostgresSQL are at least partially written in C. Uses TodayĪccording to Toptal, UNIX operating systems are written in C and most of Linux is also in C. Currently, we are on the fourth standard of C, known as C18 as it was published in June of 2018 JavaTpoint. The C standard was ratified as ANSI X3.159-1989 “Programming Language C”. Five years later, the American National Standard Institute (ANSI) formed the committee, X3J11, to establish the formal standard of C. In 1978, Brian Kernighan and Dennis Ritchie published The C Programming Language, which would serve as the language reference until a formal standard was adopted. By the middle of the 1970s, the C-based Unix was used in many projects within the Bell System as well as “a small group of research-oriented industrial, academic, and government organizations outside ”. The language and compiler were strong enough to permit us to rewrite the Unix kernel for the PDP-11 in C during the summer of the year.” This now meant that C was becoming a strong language that could, and would be, implemented across many systems. According to the Bell Labs paper, “By early 1973, the essentials of modern C were complete. The development of C was to become the basis for Unix. Early Implementations and Language Standard This led to Ritchie improving on B, and thus creating C. However, not many utilities were ever written in B due to its slow nature and inability to take advantage of PDP-11 features in the operating system. Thompson modified the BCPL system language and created B. Derived from the typeless language BCPL, it evolved a type structure created on a tiny machine as a tool to improve a meager programming environment.” Originally, Ken Thompson, a Bell Labs employee, desired to make a programming language for the new Unix platform. According to the Bell Labs paper The Development of the C Language by Dennis Ritchie, “The C programming language was devised in the early 1970s as a system implementation language for the nascent Unix operating system. The C programming language came out of Bell Labs in the early 1970s. There are many offshoots of the C programming language, including Objective-C, C++, and C#. In this article, we have learned how to check the command history of the last few days in Linux.There are many programming languages in use today, one of which is C. bash_profile exists, the operator '>‘ will append the export statement to the file, otherwise, it creates the file and writes the statement. $ export HISTTIMEFORMAT='%F %t' > ~/.bash_profile To permanently add the variable to the shell profile, add the export statement to your shell profile file (every command from which runs at the start of a shell).įor example, in the case of ‘ Bash‘, run the following to export the variable permanently. Permanently Set History Date and Time for Each Command Now, when we export the variable ‘ HISTTIMEFORMAT‘ to the shell profile from the command line, it is exported just for the session, i.e., till the time the terminal is running, after which the variable is removed from the shell profile. Using this way, you can specify the dates as patterns for the last 'N' days, or some other combination of dates, and thus get command history for all those dates.įor example, to get command history from the last third to last the fifth date, you can use: $ history | grep -E '||' Similarly, you can also filter the output for multiple key dates. ![]() ![]() Now, you can pipe the above history command output to ‘ grep‘ to get a history of commands executed on a particular date.
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