ed

---
tags: [ ed ]
---

# File and buffer management

:e {file}       load file to buffer
:q              quit
:Q              quit without saving changes
:f {name}       change buffer name
:w              write to file using current buffer name 
:w {file}       write buffer to new file
:wq             write buffer to existing file and exit

# Line-oriented addressing and movement 
#   `ed' uses line addresses to move around and operate within a buffer
#   Move to or operate on single lines by entering the line number
#   Move to or operate on ranges of lines using comma-separated values
#   The active line is always set to the last number of the range entered

. or p          display current line
n               display current line with line number

1,$ or ,        range indicating the entire buffer; displays final line

3 or 3p         move to line 3 of the buffer and display
3n              move to line 3 of the buffer and display with line number

1,$p or ,p      display entire buffer without line numbers
1,$n or ,n      display entire buffer with line numbers

15,25p          display lines 15 through 25 of the buffer
15,25n          display lines 15 through 25 of the buffer with line numbers

# Line editing commands
#   All commands can be prefixed with line addresses/ranges

i               start editing by inserting new text before the current line
a               start editing by inserting new text after the current line
c               clear contents of current line and replace with new text
.               a period [.] enterd alone on a new line ends the active edit

d               delete current line
1,3d            delete lines 1 through 3

u               undo last edit

r {file}        read contents of {file} into buffer after current line
r !{command}    read output of {command} into buffer after current line

# Example of a simple editing session

e test.txt                      edit file "test.txt"
45                              `ed' returns character count as confirmation
1,3n                            display lines 1 through 3 with line numbers
1    This is line 1           
2    This is line 2
3    This is line 3
2c                              change line 2
I am typing a new line 2
.                               end active edit 
1,3n                            display lines 1 thorugh 3 with line numbers
1    This is line 1
2    I am typing a new line 2
3    This is line 3
wq                              write file "test.txt" and exit

# Search
#   Accepts regexps in search strings

g/foo/          search all lines for `foo' and display matching lines
g/foo/n         search all lines for `foo'; display with line numbers

4,9/foo/        search lines 1 through 5 for `foo' and display matches 
4,9/foo/n       search lines 1 through 5 for `foo'; display with line numbers

# Replace
#   Accepts regexps in search and replace strings

s/foo/bar       replace first instance of `foo' with `bar' on the current line
s/foo/bar/{n}   replace {n}th instance of `foo' with `bar' on the current line
s/foo/bar/g     replace all instances of `foo' with `bar' on the current line

1,4/foo/bar/g   replace all instances of `foo' with `bar` in lines 1 through 4

,s/foo/bar/g    replace all instances of `foo' with `bar' in the entire buffer