cleaned up docs

This commit is contained in:
alm 1993-04-14 12:22:59 +00:00
parent e748ae8f6b
commit babc5cf00d
3 changed files with 42 additions and 41 deletions

View File

@ -1,16 +1,18 @@
This version of ed is not strictly POSIX compliant, as described in the
POSIX 1003.2 Draft 11.2 document (see the file `ed-1003.2'). BSD commands
have been implemented wherever they do not conflict with the POSIX
standard. In addtion, the POSIX rule that says a range of addresses
cannot be used where only a single address is expected has been relaxed
(see the file `legal-addrs').
standard. For backwards compatibility, the POSIX rule that says a range
of addresses cannot be used where only a single address is expected has
been relaxed (see the file `legal-addrs').
The BSD which have been added include the BSD `W' command for appending
text to an existing file, the BSD `s' command (i.e., s[rgp]*) to repeat
a previous substitution, the BSD `z' command for scrolling through the
buffer, and the BSD `wq' command for exiting after write. The BSD line
addressing syntax (i.e., `^' and `%' - see the file `legal.addrs') is also
recognized.
The BSD commands included are:
1) the `W' command for appending text to an existing file,
2) the `s' command (i.e., s[rgp]*) to repeat a previous substitution,
3) the `z' command for scrolling through the buffer, and
4) the `wq' command for exiting after a write.
BSD line addressing syntax (i.e., `^' and `%' - see the file
`legal.addrs') is also recognized.
The POSIX interactive global commands `G' and `V' are extended to support
multiple commands, including `a', `i' and `c'. The command format is the
@ -18,35 +20,35 @@ same as for the global commands `g' and `v', i.e., one command per line
with each line, except for the last, ending in a backslash (\).
If crypt is available, files can be read and written using DES encryption.
The `x' command prompts the user to enter a key for encrypting/decrypting
subsequent reads and writes. If only a newline is entered as the key,
then encryption is disabled. Otherwise, a key is read with echoing turned
off until a newline is entered. For more information on the encryption
algorithm, see the bdes(1) man page. Encryption/decryption should be
fully compatible with SunOS DES.
The `x' command prompts the user to enter a key used for encrypting/
decrypting subsequent reads and writes. If only a newline is entered as
the key, then encryption is disabled. Otherwise, a key is read in the
same manner as a password entry. The key remains in effect until
encryption is disabled. For more information on the encryption algorithm,
see the bdes(1) man page. Encryption/decryption should be fully compatible
with SunOS DES.
An extension to the POSIX file commands `E', `e', `r', `W' and `w' is that
<file> arguments are processed for backslash (\) escapes, i.e., any
character preceded by a backslash is interpreted literally. A trailing
backslash is ignored. If the first unescaped character of a <file>
argument is a bang (!), then the rest of the line is interpreted as a
shell command and no escape processing is performed by ed. This rule does
not apply to the 'f' command (described below).
<file> arguments are processed for backslash escapes, i.e., any character
preceded by a backslash is interpreted literally. A trailing backslash
is ignored. If the first unescaped character of a <file> argument is a
bang (!), then the rest of the line is interpreted as a shell command,
and no escape processing is performed by ed. This rule does not apply to
the 'f' command (described below).
While the default file name cannot be set to a shell command (i.e.,
!<shell-cmd>) via any of the `r', `w', and `e' commands, POSIX evidently
does not preclude using the `f' command for this purpose. Upon reading
or writing the default file when its name begins with a bang (!), ed
or writing the default file when its name begins with a bang, ed
interprets the rest of the line as a shell command and attempts to execute
it. Escape processing is not performed in this case. The `f' command
can be used in this way as a simple macro function. For example, after
setting the default file name to `!echo hello, world', the command `.r'
inserts the line `hello world' after the current line. The `f' command
with no arguments prints the default unescaped file name.
it. Escape processing is not performed in this case.
If ed is invoked with a name argument prefixed by a bang, then the
remainder of the argument is interpreted as a shell command. To invoke
ed on a file whose name starts with bang, prefix the name with a backslash.
--
The following commands are neither part of POSIX 1003.2 D11/2 nor are
they supported in this version of ed.
they supported in this version of ed.
The vi command: (addr1,addr2) !<shell-cmd> which replaces a range of
lines with the output of a shell command is not supported.

View File

@ -4,7 +4,7 @@ both BSD and POSIX.
An address represents the number of a line in the editor buffer. It is
constructed from one of the bases in the table below, optionally followed
by an absolute offset. The offset may include any combination
of digits, operators (i.e., `+', `-' and `^') and whitespace.
of digits, operators (i.e., `+', `-' and `^') and whitespace.
Addresses are read from left to right, and their values are computed
relative to the current address (i.e., the number reported by the command
`.=').
@ -14,7 +14,7 @@ address 0. 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
semi-colon. The value of the first address in a range should exceed the
semi-colon. The value of the first address in a range cannot exceed the
value of the the second. If an n-tuple of addresses is given where
n > 2, then the corresponding range is determined by the last two addresses
in the n-tuple. If only one address is expected, then then the last
@ -45,16 +45,15 @@ $ - last line
lower case letter
Examples:
The address tuple `4;+1' is equivalent to the address pair `4,5'.
The address tuple `1;+2,+3' is equivalent to the pair `3,4'.
The address tuple `1;+2;+3' is equivalent to the pair `3,6'.
The address tuple `4;+1' is equivalent to the address range `4,5'.
The address tuple `1;+2,+3' is equivalent to the range `3,4'.
The address tuple `1;+2;+3' is equivalent to the range `3,6'.
The command `1;m+' swaps the first and second lines.
The command `0;/pat/;//r !date' reads the output of the shell command
`date' to after the second line containing the pattern pat.
The command `0;/pat/r file' reads `file' to after the line containing the
pattern pat.
The command `t0;/pat/' copies the current line to after the first line
containing the patter pat.
containing the pattern pat.
The last two examples above violate the POSIX rule that says a range cannot
be used where at most a single address is expected. This rule has been
relaxed to enable such syntax. An alternative approach is to redefine
the semi-colon as a binary operator that yields a single address.
relaxed to enable such syntax.

View File

@ -12,7 +12,7 @@ E <file> - edit a file unconditionally {1}
E !<shell-cmd> - edit the standard output of <shell-cmd> {1} (POSIX)
e <file> - edit a file {1}
e !<shell-cmd> - edit the standard output of shell-cmd {1} (POSIX)
f <file> - set the default file to <file> {1}
f <file> - set the default file to <file> {1}
(1,$)G/pat/ - interactively edit lines matching a pattern (POSIX) {1}
(1,$)g/pat/<cmd-list> - apply <cmd-list> to lines matching a pattern
H - print explanations of all errors (POSIX)
@ -41,8 +41,8 @@ u - undo the last command (POSIX)
(1,$)w <file> - write lines in the buffer to a file
(1,$)w !<shell-cmd> - write lines to the stdin of <shell-cmd> (POSIX)
x - prompt for an encryption key (SunOS) {1}
(.,.+rows)z<rows> - page <rows> lines at a time to stdout (BSD)
(.,.)<newline> - print lines to stdout (BSD)
(.+1)z<rows> - page <rows> lines at a time to stdout (BSD)
(.)<newline> - print line to stdout (BSD)
--
{1} See the file `extensions' for additional information on these