ED(1) User Commands ED(1) NAME ed - text editor SYNOPSIS ed [file] DESCRIPTION ed is a line-oriented text editor. It is used to create, display, modify and otherwise manipulate text files. This version of ed implements most of the commands in the standard ed utility. It does not allow wildcard or escape characters in the search or replacement strings, and it cannot execute shell commands. It also does not implement the undo command, and it only allows one command per line. There are two non-standard commands supported that provide assistance in using ed. The 'h' command will print help information that summarizes the commands available in ed. A 'V' command was added to provide an enhanced visualization mode, which prints the text around the current line after executing a command. If invoked with a file argument, a copy of file is read into the editor's buffer. Changes are made to this copy and not directly to file itself. Upon quitting ed, any changes not explicitly saved with a 'w' command are lost. Editing is done in two distinct modes: command and input. When first invoked, ed is in command mode. In this mode commands are read from the standard input and executed to manipulate the contents of the editor buffer. A typical command might look like: ,s/old/new/g which replaces all occurrences of the string old with new. When an input command, such as 'a' (append), 'i' (insert) or 'c' (change), is given, ed enters input mode. This is the primary means of adding text to a file. In this mode, no commands are available; instead, the standard input is written directly to the editor buffer. Lines consist of text up to and including a newline character. Input mode is terminated by entering a single period (.) on a line. All ed commands operate on whole lines or ranges of lines; e.g., the 'd' command deletes lines; the 'm' command moves lines, and so on. It is possible to modify only a portion of a line by means of replacement, as in the example above. However even here, the 's' command is applied to whole lines at a time. In general, ed commands consist of zero or more line addresses, followed by a single character command and possibly additional parameters; i.e., commands have the structure: [address [,address]]command[parameters] The address(es) indicate the line or range of lines to be affected by the command. If fewer addresses are given than the command accepts, then default addresses are supplied. OPTIONS file Specifies the name of a file to read. The default filename is set to the specified file. LINE ADDRESSING An address represents the number of a line in the buffer. ed maintains a current address which is typically supplied to commands as the default address when none is specified. When a file is first read, the current address is set to the last line of the file. In general, the current address is set to the last line affected by a command. A line address is constructed from one of the bases in the list below, optionally followed by a numeric offset. The offset may include any combination of digits, operators (i.e. + and -). Addresses are read from left to right, and their values are computed relative to the current address. One exception to the rule that addresses represent line numbers is the address 0 (zero). This means "before the first line," and is legal wherever it makes sense. An address range is two addresses separated either by a comma or semicolon. The value of the first address in a range cannot exceed the value of the second. If only one address is given in a range, then the second address is set to the given address. If only one address is expected, then the last address is used. Each address in a comma-delimited range is interpreted relative to the current address. In a semicolon-delimited range, the first address is used to set the current address, and the second address is interpreted relative to the first. The following address symbols are recognized. . The current line (address) in the buffer. $ The last line in the buffer. n The nth, line in the buffer where n is a number in the range [0,$]. - The previous line. This is equivalent to -1. -n The nth previous line, where n is a non-negative number. + The next line. This is equivalent to +1. +n The nth next line, where n is a non-negative number. , The first through last lines in the buffer. This is equivalent to the address range 1,$. ; The current through last lines in the buffer. This is equivalent to the address range .,$. /re/ The next line containing the regular expression re. The search wraps to the beginning of the buffer and continues down to the current line, if necessary. // repeats the last search. ?re? The previous line containing the regular expression re. The search wraps to the end of the buffer and continues up to the current line, if necessary. ?? repeats the last search. REGULAR EXPRESSIONS Regular expressions are patterns used in selecting text. For example, the ed command g/string/ prints all lines containing string. Regular expressions are also used by the 's' command for selecting old text to be replaced with new. This version of ed does not use any wildcard or escape characters. COMMANDS All ed commands are single characters, though some require additional parameters. ed commands must fit in a single line, and cannot be continued to another line. In general, only one command is allowed per line. The only exceptions are the 'g' and 'v' commands, which can be followed by an 's', 'p', 'l' or 'n' command. ed recognizes the following commands. The commands are shown together with the default address or address range supplied if none is specified (in parenthesis). (.)a Appends text to the buffer after the addressed line, which may be the address 0 (zero). Text is entered in input mode. The current address is set to last line entered. (.,.)c Changes lines in the buffer. The addressed lines are deleted from the buffer, and text is appended in their place. Text is entered in input mode. The current address is set to last line entered. (.,.)d Deletes the addressed lines from the buffer. If there is a line after the deleted range, then the current address is set to this line. Otherwise the current address is set to the line before the deleted range. e file Edits file, and sets the default filename. If file is not specified, then the default filename is used. Any lines in the buffer are deleted before the new file is read. The current address is set to the last line read. E file Edits file unconditionally. This is similar to the e command, except that unwritten changes are discarded without warning. The current address is set to the last line read. f file Sets the default filename to file. If file is not specified, then the default filename is printed. (1,$)g/re/command Applies command to each of the addressed lines matching a regular expression re. The current address is set to the line currently matched before command is executed. At the end of the 'g' command, the current address is set to the last line affected by command. The allowable commands are 's', 'p', 'l' and 'n'. The 'p' command is used if command is not specified. h Print help information, which summarizes the commands available. Note that this is different than the standard usage for 'h', which prints an explanation of the last error. (.)i Inserts text in the buffer before the current line. Text is entered in input mode. The current address is set to the last line entered. (.,.+1)j Joins the addressed lines. The addressed lines are deleted from the buffer and replaced by a single line containing their joined text. The current address is set to the resultant line. (.,.)l Prints the addressed lines unambiguously. The current address is set to the last line printed. (.,.)m(.) Moves lines in the buffer. The addressed lines are moved to after the right-hand destination address, which may be the address 0 (zero). The current address is set to the new address of the last line moved. (.,.)n Prints the addressed lines along with their line numbers. The current address is set to the last line printed. (.,.)p Prints the addressed lines. The current address is set to the last line printed. P Toggles the command prompt on and off. The command prompt is by default turned off. q Quits ed. Q Quits ed unconditionally. This is similar to the q command, except that unwritten changes are discarded without warning. ($)r file Reads file to after the addressed line. If file is not specified, then the default filename is used. If there was no default filename prior to the command, then the default filename is set to file. Otherwise, the default filename is unchanged. The current address is set to the last line read. (.,.)s/re/replacement/ (.,.)s/re/replacement/g Replaces text in the addressed lines matching a regular expression re with replacement. By default, only the first match in each line is replaced. If the 'g' (global) suffix is given, then every match to be replaced. It is an error if no substitutions are performed on any of the addressed lines. The current address is set to the last line affected. (.,.)t(.) Copies (i.e., transfers) the addressed lines to after the right- hand destination address, which may be the address 0 (zero). The current address is set to the last line copied. (1,$)v/re/command-list Applies command-list to each of the addressed lines not matching a regular expression re. This is similar to the 'g' command. Vn If n is specified, the visualization mode is enabled and the number of lines printed is set to n. Otherwise, the visualization mode it toggled on or off. The visualization mode is a non-standard feature that prints the text in the edit buffer before and after the current line. (1,$)w file Writes the addressed lines to file. Any previous contents of file is lost without warning. If there is no default filename, then the default filename is set to file, otherwise it is unchanged. If no filename is specified, then the default filename is used. The current address is unchanged. (.)x Copies (puts) the contents of the cut buffer to after the addressed line. The current address is set to the last line copied. (.,.)y Copies (yanks) the addressed lines to the cut buffer. The cut buffer is overwritten by subsequent 'y', 'j', 'd', or 'c' commands. The current address is unchanged. (.+1)zn Scrolls n lines at a time starting at addressed line. If n is not specified, then the current window size is used. The current address is set to the last line printed. ($)= Prints the line number of the addressed line. (.+1)newline Prints the addressed line, and sets the current address to that line. SEE ALSO B. W. Kernighan and P. J. Plauger, Software Tools in Pascal , Addison- Wesley, 1981. LIMITATIONS ed is limited to 200 characters per line. If an input line is greater than 200 characters it will be broken up into multiple lines. The input file must terminate lines with a newline (LF) character. Files will be written using the UNIX LF line termination. The size of the file is limited by the amount of buffer memory available to ed. If ed encounters an error in a command line it will print '?' and return to command mode. Attempting to quit ed or edit another file before writing a modified buffer results in an error. If the command is entered a second time, it succeeds, but any changes to the buffer are lost. AUTHOR Dave Hein COPYRIGHT Copyright (c) 2011, 2012, Dave Hein MIT License (See license.txt in the root directory) This is free software: you are free to change and redistribute it. There is no warranty, to the extent permitted by law. SPINIX utility March 2012 ED(1)