![]() and shall be removed before splitting the input into tokens. If a follows the, the shell shall interpret this as line continuation. 2.2.1 Escape Character (Backslash)Ī that is not quoted shall preserve the literal value of the following character, with the exception of a The here-document represents anotherįorm of quoting see Here-Document. The various quoting mechanisms are the escape character, single-quotes, and double-quotes. That is, these characters may be special depending onĬonditions described elsewhere in this volume of POSIX.1-2017: * ? [ # = % The application shall quote the following characters if they are to represent themselves: | & ( ) $ ` \ " ' Īnd the following may need to be quoted under certain circumstances. Parameter expansion and command substitution within here-document processing (see Here-Document). Literal meaning of the special characters in the next paragraph, prevent reserved words from being recognized as such, and prevent ![]() Quoting is used to remove the special meaning of certain characters or words to the shell. The shell optionally waits for the command to complete and collects the exit status (see Exit Status for Script) as the positional parameter numbered 0 (see Command Search and Execution). Parameters numbered 1 to n, and the name of the command (or in the case of a function within a script, the name of the The shell executes a function (see Function Definition Command), built-in (see Special Built-In Utilities), executable file, or script, giving the names of the arguments as positional The shell performs redirection (see Redirection) and removes redirection operators and their operands The shell performs various expansions (separately) on different parts of each command, resulting in a list of pathnames andįields to be treated as a command and arguments see wordexp. The shell parses the input into simple commands (see Simple Commands) and compound commands (see Compound Commands). The shell breaks the input into tokens: words and operators see Token Recognition. If the first line of a file of shell commands starts with the characters In the System Interfaces volume of POSIX.1-2017. The shell reads its input from a file (see sh), from the -c option or from the The specific details are included in the cited The shell operates according to the following general overview of operations. This chapter describes the syntax of that command language as it is used by the sh utility and the system() and popen() functions defined in the System Interfaces volume of POSIX.1-2017. The shell is a command language interpreter. This chapter contains the definition of the Shell Command Language. The Open Group Base Specifications Isedition
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