ed(1) ed(1)NAME ed, red - text editor SYNOPSIS ed [-] [-p string] [-x] [file] red [-] [-p string] [-x] [file] DESCRIPTION ed is the standard text editor. If the file argument is given, ed simulates an e command (see below) on the named file; that is to say, the file is read into ed's buffer so that it can be edited. The optional - suppresses the print- ing of character counts by e, r, and w commands, of diagnos- tics from e and q commands, and of the ! prompt after a !shell command. The -p flag option allows the user to specify a prompt string. The string must be enclosed in dou- ble quotes. If -x is present, an X command is simulated first to handle an encrypted file. ed operates on a copy of the file it is editing; changes made to the copy have no ef- fect on the file until a w (write) command is given. The copy of the text being edited resides in a temporary file called the buffer. There is only one buffer. red is a restricted version of ed. It will allow editing of files only in the current directory. It prohibits executing shell commands via !shell command. Attempts to bypass these restrictions result in the error message: restricted shell Both ed and red support the fspec(4) formatting capability. After including a format specification as the first line of file and invoking ed with your terminal in stty -tabs or stty tab3 mode (see stty(1), the specified tab stops will be used automatically when scanning file. For example, if the first line of a file contained: <:t5,10,15 s72:> tab stops would be set at columns 5, 10, and 15, and a max- imum line length of 72 would be imposed. Note: While entering text, tab characters, when typed, are expanded to every eighth column, as is the default. Commands to ed have a simple and regular structure: zero, one, or two addresses followed by a single-character com- mand, followed by any applicable parameters to that command. These addresses specify one or more lines in the buffer. April, 1990 1
ed(1) ed(1)Every command that requires addresses has default addresses, so that the addresses very often can be omitted. In general, only one command may appear on a line. Certain commands allow the input of text. This text is placed in the appropriate place in the buffer. While ed is accepting text, it is said to be in ``input mode.'' In this mode, no commands are recognized; all input is merely collected. In- put mode is left by typing a period (.) alone at the begin- ning of a line. ed supports a limited form of ``regular expression'' (RE) notation; regular expressions are used in addresses to specify lines and in some commands (e.g., s) to specify por- tions of a line that are to be substituted. A regular ex- pression specifies a set of character strings. A member of this set of strings is said to be matched by the RE. The REs allowed by ed are constructed as follows: The following one-character REs match a single character: 1.1 An ordinary character (not one of those discussed in 1.2 below) is a one-character RE that matches itself. 1.2 A backslash (\) followed by any special character is a one-character RE that matches the special character itself. The special characters are: a. ., *, [, and \ (period, asterisk, left square bracket, and backslash, respectively), which are always special, except when they appear within square brackets ([]; see 1.4 below). b. ^ (circumflex), which is special at the beginning of an entire RE (see 3.1 and 3.2 below), or when it immediately follows the left of a pair of square brackets ([]) (see 1.4 below). c. $ (currency symbol), which is special at the end of an entire RE (see 3.2 below). d. The character used to bound (i.e., delimit) an entire RE, which is special for that RE (for ex- ample, see how slash (/) is used in the g com- mand, below.) 1.3 A period (.) is a one-character RE that matches any character except newline. 1.4 A nonempty string of characters enclosed in square brackets ([]) is a one-character RE that matches any one character in that string. If, however, the first 2 April, 1990
ed(1) ed(1)character of the string is a circumflex (^), the one- character RE matches any character except newline and the remaining characters in the string. The ^ has this special meaning only if it occurs first in the string. The minus (-) may be used to indicate a range of consecutive ASCII characters; for example, [0-9] is equivalent to [0123456789]. The - loses this special meaning if it occurs first (after an initial ^, if any) or last in the string. The right square bracket (]) does not terminate such a string when it is the first character within it (after an initial ^, if any); e.g., []a-f] matches either a right square bracket (]) or one of the letters a through f, in- clusive. The four characters listed in 1.2.a (above) stand for themselves within such a string of charac- ters. The following rules may be used to construct REs from one- character REs: 2.1 A one-character RE is a RE that matches whatever the one-character RE matches. 2.2 A one-character RE followed by an asterisk (*) is a RE that matches zero or more occurrences of the one- character RE. If there is any choice, the longest leftmost string that permits a match is chosen. 2.3 A one-character RE followed by \{m\}, \{m,\}, or \{m,n\} is a RE that matches a range of occurrences of the one-character RE. The values of m and n must be non-negative integers less than 256: \{m\} matches exactly m occurrences; \{m,\} matches at least m occurrences; \{m,n\} matches any number of occurrences between m and n inclusive. Whenever a choice exists, the RE matches as many oc- currences as possible. 2.4 The concatenation of REs is a RE that matches the con- catenation of the strings matched by each component of the RE. 2.5 A RE enclosed between the character sequences \( and \) is a RE that matches whatever the unadorned RE matches. 2.6 The expression \n matches the same string of charac- April, 1990 3
ed(1) ed(1)ters as was matched by an expression enclosed between \( and \) earlier in the same RE. Here n is a digit; the sub-expression specified is that beginning with the n-th occurrence of \( counting from the left. For example, the expression ^\(.*\)\1$ matches a line con- sisting of two repeated appearances of the same string. Finally, an entire RE may be constrained to match only an initial segment or final segment of a line (or both). 3.1 A caret (^) at the beginning of an entire RE con- strains that RE to match an initial segment of a line. 3.2 A currency symbol ($) at the end of an entire RE con- strains that RE to match a final segment of a line. The construction ^entire RE$ constrains the entire RE to match the entire line. The null RE (e.g., //) is equivalent to the last RE encoun- tered. See the paragraph before FILES, below. To understand addressing in ed, it is necessary to know that at any time there is a current line. Generally speaking, the current line is the last line affected by a command; the exact effect on the current line is discussed under the description of each command. addresses are constructed as follows: 1. The character . addresses the current line. 2. The character $ addresses the last line of the buffer. 3. A decimal number n addresses the n-th line of the buffer. 4. 'x addresses the line marked with the mark name char- acter x, which must be a lowercase letter. Lines are marked with the k command (described below). If x was not used to mark a line, 'x addresses line 0. 5. A RE enclosed by slashes (/) addresses the first line found by searching forward from the line following the current line toward the end of the buffer and stopping at the first line containing a string matching the RE. If necessary, the search wraps around to the beginning of the buffer and continues up to and including the current line, so that the entire buffer is searched. See the paragraph before FILES, below. 6. A RE enclosed in question marks (?) addresses the 4 April, 1990
ed(1) ed(1)first line found by searching backward from the line preceding the current line toward the beginning of the buffer and stopping at the first line containing a string matching the RE. If necessary, the search wraps around to the end of the buffer and continues up to and including the current line. See also the last paragraph before FILES, below. 7. An address followed by a plus sign (+) or a minus sign (-) followed by a decimal number specifies that ad- dress plus (respectively minus) the indicated number of lines. The plus sign may be omitted. 8. If an address begins with + or -, the addition or sub- traction is taken with respect to the current line; e.g, -5 is understood to mean .-5. 9. If an address ends with + or -, then 1 is added to or subtracted from the address, respectively. As a consequence of this rule and of rule 8 immediately above, the address - refers to the line preceding the current line. (To maintain compatibility with earlier versions of the editor, the character ^ in addresses is entirely equivalent to -.) Moreover, trailing + and - characters have a cumulative effect, so -- refers to the current line less 2. 10. For convenience, a comma (,) stands for the address pair 1,$, while a semicolon (;) stands for the pair .,$. Commands may require zero, one, or two addresses. Commands that require no addresses regard the presence of an address as an error. Commands that accept one or two addresses as- sume default addresses when an insufficient number of ad- dresses is given; if more addresses are given than such a command requires, the last one(s) are used. Typically, addresses are separated from each other by a com- ma (,). They may also be separated by a semicolon (;). In the latter case, the current line (.) is set to the first address, and only then is the second address calculated. This feature can be used to determine the starting line for forward and backward searches (see rules 5. and 6. above). The second address of any two-address sequence must correspond to a line that follows, in the buffer, the line corresponding to the first address. In the following list of ed commands, the default addresses are shown in parentheses. The parentheses are not part of the address; they show that the given addresses are the de- fault. April, 1990 5
ed(1) ed(1)It is generally illegal for more than one command to appear on a line. Any command (except e, f, r, or w) may be suf- fixed by l, n or p, however, in which case the current line is either listed, numbered or printed, respectively, as dis- cussed below under the l, n and p commands. (.)a text . The append command reads the given text and ap- pends it after the addressed line; . is left at the last inserted line, or, if there were none, at the addressed line. Address 0 is legal for this command: it causes the appended text to be placed at the beginning of the buffer. The max- imum number of characters that may be entered from a terminal is 256 per line (including the newline character). (.)c text . The change command deletes the addressed lines, then accepts input text that replaces these lines; . is left at the last line input, or, if there were none, at the first line that was not deleted. (.,.)d The delete command deletes the addressed lines from the buffer. The line after the last line deleted becomes the current line; if the lines deleted were originally at the end of the buffer, the new last line becomes the current line. e file The edit command causes the entire contents of the buffer to be deleted, and then the named file to be read in; . is set to the last line of the buffer. If no file name is given, the currently-remembered filename, if any, is used (see the f command). The number of characters read is typed; file is remembered for possible use as a default filename in subsequent e, r, and w commands. If file is replaced by !, the rest of the line is taken to be a shell (sh(1)) com- mand whose output is to be read. Such a shell command is not remembered as the current filename. See also DIAGNOSTICS, below. E file The E command is like e, except that the editor does not check to see if any changes have been made to the buffer since the last w command. f file If file is given, this command changes the currently-remembered filename to file; otherwise, it prints the currently-remembered filename. 6 April, 1990
ed(1) ed(1)(1,$)g/RE/command list In the global command, the first step is to mark every line that matches the given RE. Then, for every such line, the given command list is exe- cuted with . initially set to that line. A sin- gle command or the first of a list of commands appears on the same line as the global command. All lines of a multi-line list except the last line must be ended with a \; a, i, and c commands and associated input are permitted. The . ter- minating input mode may be omitted if it would be the last line of the command list. An empty com- mand list is equivalent to the p command. (1,$)G/RE/ In the interactive global command, the first step is to mark every line that matches the given RE. Then, for every such line, that line is printed, . is changed to that line, and any one command (other than one of the a, c, i, g, G, v, and V commands) may be input and is executed. After the execution of that command, the next marked line is printed, and so on; a newline acts as a null command; an & causes the re-execution of the most recent command executed within the current invocation of G. Note that the commands input as part of the execution of the G command may ad- dress and affect any lines in the buffer. The G command can be terminated by an interrupt signal (ASCII DELETE or BREAK). A command that causes an error terminates the G command. h The help command gives a short error message that explains the reason for the most recent ? diag- nostic. H The Help command causes ed to enter a mode in which error messages are printed for all subse- quent ? diagnostics. It will also explain the previous ? if there was one. The H command al- ternately turns this mode on and off; it is ini- tially off. (.)i text . The insert command inserts the given text before the addressed line; . is left at the last insert- ed line, or, if there were none, at the addressed line. This command differs from the a command only in the placement of the input text. Address 0 is not legal for this command. The maximum number of characters that may be entered from a terminal is 256 per line (including the newline character). April, 1990 7
ed(1) ed(1)(.,.+1)j Join contiguous lines by removing the appropriate newline characters. If exactly one address is given, this command does nothing. (.)kx Mark the addressed line with name x, which must be a lowercase letter. The address 'x then ad- dresses this line; . is unchanged. (.,.)l List the addressed lines in an unambiguous way: a few nonprinting characters (e.g., tab, back- space) are represented by mnemonic overstrikes. All other nonprinting characters are printed in octal, and long lines are folded. An l command may be appended to any other command other than e, f, r, or w. (.,.)ma Move addressed line(s) to after the line ad- dressed by a. Address 0 is legal for a and causes the addressed line(s) to be moved to the beginning of the file. It is an error if address a falls within the range of moved lines; . is left at the last line moved. (.,.)n Prints the addressed lines, preceding each line by its line number and a tab character; . is left at the last line printed. The n command may be appended to any other command other than e, f, r, or w. (.,.)p Print the addressed lines; . is left at the last line printed. The p command may be appended to any other command other than e, f, r, or w. For example, dp deletes the current line and prints the new current line. P The editor will prompt with a * for all subse- quent commands. The P command alternately turns this mode on and off; it is initially off. q Exit. ed No automatic write of a file is done (but see DIAGNOSTICS, below). Q Exit ed without checking if changes have been made in the buffer since the last w command. ($)r file The read command reads in the given file after the addressed line. If no filename is given, the currently-remembered filename, if any, is used (see e and f commands). The currently-remembered filename is not changed unless file is the very first filename mentioned since ed was invoked. Address 0 is legal for r and causes the file to 8 April, 1990
ed(1) ed(1)be read at the beginning of the buffer. If the read is successful, the number of characters read is typed; . is set to the last line read in. If file is replaced by !, the rest of the line is taken to be a shell (sh(1)) command whose output is to be read. For example, $r !ls appends current directory to the end of the file being edited. Such a shell command is not remembered as the current filename. (.,.)s/RE/replacement/ or (.,.)s/RE/replacement/g or (.,.)s/RE/replacement/n Search each addressed line for an occurrence of the specified RE. In each line in which a match is found, all (nonoverlapped) matched strings are replaced by the replacement if the global re- placement indicator g appears after the command. If the global indicator does not appear, only the first occurrence of the matched string is re- placed. Sometimes substitution of an RE results in the last (or only) affected line being printed out. This occurs only when substitution is not global or of an nth occurrence. If a number n appears after the command, only the nth oc- currence of the matched string on each addressed line is replaced. It is an error for the substi- tution to fail on all addressed lines. Any char- acter other than space or newline may be used in- stead of / to delimit the RE and the replacement; . is left at the last line on which a substitu- tion occurred. See the paragraph before FILES, below. An ampersand (&) appearing in the replacement is replaced by the string matching the RE on the current line. The special meaning of & in this context may be suppressed by preceding it by \. As a more general feature, the characters \n, where n is a digit, are replaced by the text matched by the n-th regular subexpression of the specified RE enclosed between \( and \). When nested parenthesized subexpressions are present, n is determined by counting occurrences of \( starting from the left. When the character % is the only character in the replacement, the re- placement used in the most recent substitute com- mand is used as the replacement in the current substitute command. The % loses its special meaning when it is in a replacement string of more than one character or is preceded by a \. April, 1990 9
ed(1) ed(1)A line may be split by substituting a newline character into it. The newline in the replace- ment must be escaped by preceding it by \. Such substitution cannot be done as part of a g or v command list. (.,.)ta Similar to the move (m) command, except that a copy of the addressed lines is placed after ad- dress a (which may be 0); . is left at the last line of the copy. u Undo the most recent command that modified any- thing in the buffer, namely the most recent a, c, d, g, i, j, m, r, s, t, v, G, or V command. (1,$)v/RE/command list This command is the same as the global command g, except that the command list is executed with . initially set to every line that does not match the RE. (1,$)V/RE/ This command is the same as the interactive glo- bal command G except that the lines that are marked during the first step are those that do not match the RE. (1,$)w file Write the addressed lines into the named file. If the file does not exist, it is created with mode 666 (readable and writable by everyone), un- less your umask setting (see sh(1)) dictates oth- erwise. The currently-remembered filename is not changed unless file is the very first filename mentioned since ed was invoked. If no filename is given, the currently-remembered filename, if any, is used (see e and f commands); . is un- changed. If the command is successful, the number of characters written is typed. If file is replaced by !, the rest of the line is taken to be a shell (sh(1)) command whose standard in- put is the addressed lines. Such a shell command is not remembered as the current filename. X A key string is demanded from the standard input. Subsequent e, r, and w commands will encrypt and decrypt the text with this key by the algorithm of crypt(1). An explicitly empty key turns off encryption. The encryption scheme used here is not secure. ($)= The line number of the addressed line is typed; address 0 is legal for this command. . is un- 10 April, 1990
ed(1) ed(1)changed by this command. !shell command The remainder of the line after the ! is sent to the system shell (sh(1)) to be interpreted as a command. Within the text of that command, the unescaped character % is replaced with the remem- bered filename; if a ! appears as the first char- acter of the shell command, it is replaced with the text of the previous shell command. Thus, !! will repeat the last shell command. If any ex- pansion is performed, the expanded line is echoed; . is unchanged. (.+1)newline An address alone on a line causes the addressed line to be printed. A newline alone is equivalent to .+1p; it is useful for stepping forward through the buffer. If an interrupt signal (ASCII or CONTROL-c is sent, ed prints a ? and returns to its command level. Some size limitations: 512 characters per line, 256 charac- ters per global command list, 64 characters per file name, and 128K characters in the buffer. The limit on the number of lines depends on the amount of user memory: each line takes 1 word. When reading a file, ed discards ASCII NUL characters and all characters after the last newline. Files (e.g., a.out) that contain characters not in the ASCII set (bit 8 on) can- not be edited by ed. If the closing delimiter of a RE or of a replacement string (e.g., /) would be the last character before a newline, that delimiter may be omitted, in which case the addressed line is printed. The following pairs of commands are equivalent: s/s1/s2 s/s1/s2/p g/s1 g/s1/p ?s1 ?s1? EXAMPLES ed text invokes the editor with the file named text. For further examples, see ``Using ed'' in A/UX Text Editing Tools. FILES /bin/ed /bin red /tmp/e# temporary; # is the process number. April, 1990 11
ed(1) ed(1)ed.hup work is saved here if the terminal is hung up. DIAGNOSTICS ? for command errors. ?file for an inaccessible file. (use the h and H commands for detailed expla- nations). If changes have been made in the buffer since the last w command that wrote the entire buffer, ed warns the user if an attempt is made to destroy ed's buffer via the e or q commands. It prints ? and allows one to continue editing. A second e or q command will take effect at any time, pro- vided no further changes have been made to the file. The - command-line flag option inhibits this feature. SEE ALSO crypt(1), ex(1), grep(1), sed(1), sh(1), stty(1), vi(1), fspec(4), regexp(5). ``Using ed'' in A/UX Text Editing Tools. NOTES The ! command and the ! escape from the e, r, and w commands cannot be used if the the editor is invoked from a restrict- ed shell (see sh(1)). The sequence \n in a RE does not match a newline character. The l command mishandles interrupts. Files encrypted directly with the crypt(1) command with the null key cannot be edited. Characters are masked to 7 bits on input. The -x flag option and the editor command X are not imple- mented in the international distribution. If the editor input is coming from a command file (i.e., ed file < ed-cmd-file), the editor will exit at the first failure of a command that is in the command file. 12 April, 1990