A tip related to the VI editor
Often when we receive files by e-mail, we find an unwanted character "^M"
(CTRL-M) at several places. This is the control character roughly equivalent
of a carriage return. If you use vi, like I do, a natural thing is to
try and get rid of this using "global substitution", which is done using:
:g/A/s//B/g
The above command replaces string "A" by the string "B". So we can use "^M"
for "A" and " " (empty space) for "B". But then as soon as we try to type
"^M" in place of "A", it is treated as carriage return, and we are back in the
file. A way to avoid this is to type "^V" (CTRL-V) before "^M". Thus, to
simply remove all the occurances of "^M", use:
:g/^V^M/s// /g
Sometimes, this "^M" appears inadvertantly and makes the entire file as a
single line. A solution to that is to replace "^M" by itself! Thus you use:
:g/^V^M/s//^V^M/g
By the way, all the "V" and "M" when keyed with "CTRL" are
actually in lowercase and one doesn't have to use the "SHIFT" or "CAPS LOCK"
keys while entering them.
I haven't been able to easily locate these little tips even though there are
many sites devoted to "vi" such as:
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