Editing Slash (punctuation) (section)

===Computing===
The slash, sometimes distinguished as "forward slash", is used in [[computing]] in a number of ways, primarily as a separator among levels in a given hierarchy, for example in the path of a filesystem.

====File paths====
The slash is used as the [[path (computing)|path]] component separator in many [[computer]] operating systems (e.g., Unix's {{mono|pictures/image.png}}). In [[Unix]] and [[Unix-like]] systems, such as [[macOS]] and [[Linux]], the slash is also used for the [[volume (computing)|volume]] [[root directory]] (e.g., the initial slash in {{mono|/usr/john/pictures}}). Confusion of the slash with the backslash {{angle brackets|\}} largely arises from the use of the latter as the path component separator in the widely used MS-DOS and [[Microsoft Windows]] systems.<ref name="jed" /><ref name="turton" />

====Networking====
The slash is used in a similar fashion in internet [[Uniform Resource Locator|URLs]] (e.g., {{mono|<nowiki>https://en.wikipedia.org/wiki/Slash_(punctuation)</nowiki>}}).<ref name="solidhart" /> Often this portion of such URLs corresponds with files on a Unix [[computer server|server]] with the same name, and this is where this convention for [[internet]] URLs comes from.

The slash in an [[IP address]] (e.g., {{mono|192.0.2.0/29}}) indicates the prefix size in [[CIDR notation]]. The number of addresses of a [[Subnetwork|subnet]] may be calculated as 2{{sup|address size − prefix size}}, in which the address size is 128 for [[IPv6]] and 32 for [[IPv4]]. For example, in IPv4, the prefix size/29 gives: 2{{sup|32–29}} = 2{{sup|3}} = 8 addresses.

====Programming====
The slash is used as a [[#Division|division operator]] in most [[programming language]]s while [[APL (programming language)|APL]] uses it for reduction ([[Fold (higher-order function)|fold]]) and compression ([[Filter (higher-order function)|filter]]). The double slash is used by [[Rexx]] as a [[#Mod|modulo operator]], and [[Python (programming language)|Python]] (starting in version 2.2) uses a double slash for division which rounds (using [[Floor and ceiling functions|floor]]) to an integer.  In [[Raku (programming language)|Raku]] the double slash is used as a "defined-or" alternative to '''||'''. A dot and slash {{angle brackets|./}} is used in [[MATLAB]] and [[GNU Octave]] to indicate an element-by-element division of matrices.

[[comment (computer programming)|Comments]] that begin with {{mono|'''/*'''}} (a slash and an asterisk) and end with {{mono|'''*/'''}} were introduced in [[PL/I]] and subsequently adopted by [[SAS System|SAS]], [[C (programming language)|C]], Rexx, [[C++]], [[Java (programming language)|Java]], [[JavaScript]], [[PHP]], [[Cascading Style Sheets|CSS]], and [[C Sharp (programming language)|C#]]. A double slash {{mono|'''//'''}} is also used by [[C99]], C++, C#, PHP, Java, [[Swift (programming language)|Swift]], [[Pascal (programming_language)|Pascal]] and JavaScript to start a single line comment.

In [[SGML]] and derived languages such as [[HTML]] and [[XML]], a slash is used in closing tags. For example, in HTML, {{mono|&lt;b&gt;}} begins a section of {{strong|bold}} text and {{mono|&lt;/b&gt;}} closes it. In XHTML, slashes are also necessary for "self-closing" elements such as the [[newline]] command {{nowrap|{{mono|&lt;br /&gt;}}}} where HTML has simply {{nowrap|{{mono|&lt;br&gt;}}}}.

In a style originating in the [[Digital Equipment Corporation]] line of operating systems ([[OS/8]], [[RT-11]], [[TOPS-10]], et cetera), [[Windows (operating system)|Windows]], [[DOS]], some [[CP/M]] programs, [[OpenVMS]], and [[OS/2]] all use the slash to indicate [[command-line option]]s. For example, the command {{mono|dir/w}} is understood as using the command [[dir (command)|dir]] ("directory") with the "wide" option. No space is required between the command and the switch; this was the reason for the choice to use backslashes as the path separator since one would otherwise be unable to run a program in a different directory.

Slashes are used as the standard delimiters for [[regular expression]]s, although other characters can be used instead.

[[IBM JCL]] uses a double slash to start each line in a batch job stream except for /* and /&.

====Programs====
[[Internet Relay Chat|IRC]] and many in-game chat clients use the slash to mark commands, such as joining and leaving a chat room or sending private messages. For example, in IRC, {{mono|/join #services}} is a command to join the [[IRC channels|channel]] "services" and {{mono|/me}} is a command to format the following message as though it were an action instead of a spoken message. In ''[[Minecraft]]''{{'}}s chat function, the slash is used for executing console and plugin commands. In ''[[Second Life]]''{{'}}s chat function, the slash is used to select the "communications channel", allowing users to direct commands to virtual objects "listening" on different channels. For example, if a virtual house's lights were set to use channel 42, the command "/42 on" would turn them on. In [[Discord (software)|Discord]], slash commands are used to send special messages and execute commands, like sending a [[shrug|shrug emoji (¯\_(ツ)_/¯)]] or a table flip emoji ((╯°□°)╯︵ ┻━┻), or changing one's nickname using "/nick". Slash commands can also be used to use Discord bots.

The [[Gedcom]] standard for exchanging computerized genealogical data uses slashes to delimit surnames; an example would be Bill /Smith/ Jr. Slashes around surnames are also used in [[Personal Ancestral File]].