Search results
Results From The WOW.Com Content Network
sed is a line-oriented text processing utility: it reads text, line by line, from an input stream or file, into an internal buffer called the pattern space. Each line read starts a cycle . To the pattern space, sed applies one or more operations which have been specified via a sed script . sed implements a programming language with about 25 ...
Standard examples of data-driven languages are the text-processing languages sed and AWK, [1] and the document transformation language XSLT, where the data is a sequence of lines in an input stream – these are thus also known as line-oriented languages – and pattern matching is primarily done via regular expressions or line numbers.
This one-liner program is a glob pattern matcher. It understands the glob characters *, meaning zero or more characters, and ?, meaning exactly one character, just like most Unix shells. Run it with two args, the string and the glob pattern. The exit status is 0 (shell true) when the pattern matches, 1 otherwise.
A double vertical bar symbol may be used to call out a footnote. (The traditional order of these symbols in English is *, †, ‡, §, ‖, ¶, so its use is very rare; in modern usage, numbers and letters are preferred for endnotes and footnotes. [9])
an atom is either a number or a symbol; a number is an unbroken sequence of one or more decimal digits, optionally preceded by a plus or minus sign; a symbol is a letter followed by zero or more of any characters (excluding whitespace); and; a list is a matched pair of parentheses, with zero or more expressions inside it.
Generally, an escape character is not a particular case of (device) control characters, nor vice versa.If we define control characters as non-graphic, or as having a special meaning for an output device (e.g. printer or text terminal) then any escape character for this device is a control one.
With respect to a language definition, the syntax of Comments can be classified many ways, including: Line vs. block – a line comment starts with a delimiter and continues to the end of the line (newline marker) whereas a block comment starts with one delimiter and ends with another and can cross lines
An important aspect of this, setting Unix pipes apart from other pipe implementations, is the concept of buffering: for example a sending program may produce 5000 bytes per second, and a receiving program may only be able to accept 100 bytes per second, but no data is lost. Instead, the output of the sending program is held in the buffer.