Removing c-style comments with sed
I need to delete some kind of characteristic, single line C++ comments from all files in our repository. Code looks something like this:
some_code
// characteristic_comment_to_delete
some_more_code // another_comment
another_line_with_code // characteristic_comment_to_delete
even_more_code
As a result, I would like to get this:
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
I used sed command that makes my result almost as good as I would like:
#sed -i -e 's&// characteristic_comment_to_delete.*&&g' some_file.cpp
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
Unfortunately, leaving those blank lines is unacceptable solution, so I need somehow improve my command so that it removes whole line, but only if it is left blank after removing this specific comment.
linux sed
New contributor
add a comment |
I need to delete some kind of characteristic, single line C++ comments from all files in our repository. Code looks something like this:
some_code
// characteristic_comment_to_delete
some_more_code // another_comment
another_line_with_code // characteristic_comment_to_delete
even_more_code
As a result, I would like to get this:
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
I used sed command that makes my result almost as good as I would like:
#sed -i -e 's&// characteristic_comment_to_delete.*&&g' some_file.cpp
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
Unfortunately, leaving those blank lines is unacceptable solution, so I need somehow improve my command so that it removes whole line, but only if it is left blank after removing this specific comment.
linux sed
New contributor
@jimmij, the OP doesn't want to remove all comments, only// characteristic_comment_to_delete
– Stéphane Chazelas
15 hours ago
For C-style comments, How can I delete all characters falling under /* .... */ including /* & */? would be a closer match.
– Stéphane Chazelas
15 hours ago
Off topic, but you're not really running this command as root, are you? That#
prompt makes my eye twitch.
– David Conrad
12 hours ago
Possible duplicate of Remove comments in a C file
– MCCCS
12 hours ago
add a comment |
I need to delete some kind of characteristic, single line C++ comments from all files in our repository. Code looks something like this:
some_code
// characteristic_comment_to_delete
some_more_code // another_comment
another_line_with_code // characteristic_comment_to_delete
even_more_code
As a result, I would like to get this:
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
I used sed command that makes my result almost as good as I would like:
#sed -i -e 's&// characteristic_comment_to_delete.*&&g' some_file.cpp
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
Unfortunately, leaving those blank lines is unacceptable solution, so I need somehow improve my command so that it removes whole line, but only if it is left blank after removing this specific comment.
linux sed
New contributor
I need to delete some kind of characteristic, single line C++ comments from all files in our repository. Code looks something like this:
some_code
// characteristic_comment_to_delete
some_more_code // another_comment
another_line_with_code // characteristic_comment_to_delete
even_more_code
As a result, I would like to get this:
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
I used sed command that makes my result almost as good as I would like:
#sed -i -e 's&// characteristic_comment_to_delete.*&&g' some_file.cpp
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
Unfortunately, leaving those blank lines is unacceptable solution, so I need somehow improve my command so that it removes whole line, but only if it is left blank after removing this specific comment.
linux sed
linux sed
New contributor
New contributor
edited 13 hours ago
Rui F Ribeiro
40.7k1479137
40.7k1479137
New contributor
asked 17 hours ago
fortellerforteller
112
112
New contributor
New contributor
@jimmij, the OP doesn't want to remove all comments, only// characteristic_comment_to_delete
– Stéphane Chazelas
15 hours ago
For C-style comments, How can I delete all characters falling under /* .... */ including /* & */? would be a closer match.
– Stéphane Chazelas
15 hours ago
Off topic, but you're not really running this command as root, are you? That#
prompt makes my eye twitch.
– David Conrad
12 hours ago
Possible duplicate of Remove comments in a C file
– MCCCS
12 hours ago
add a comment |
@jimmij, the OP doesn't want to remove all comments, only// characteristic_comment_to_delete
– Stéphane Chazelas
15 hours ago
For C-style comments, How can I delete all characters falling under /* .... */ including /* & */? would be a closer match.
– Stéphane Chazelas
15 hours ago
Off topic, but you're not really running this command as root, are you? That#
prompt makes my eye twitch.
– David Conrad
12 hours ago
Possible duplicate of Remove comments in a C file
– MCCCS
12 hours ago
@jimmij, the OP doesn't want to remove all comments, only
// characteristic_comment_to_delete
– Stéphane Chazelas
15 hours ago
@jimmij, the OP doesn't want to remove all comments, only
// characteristic_comment_to_delete
– Stéphane Chazelas
15 hours ago
For C-style comments, How can I delete all characters falling under /* .... */ including /* & */? would be a closer match.
– Stéphane Chazelas
15 hours ago
For C-style comments, How can I delete all characters falling under /* .... */ including /* & */? would be a closer match.
– Stéphane Chazelas
15 hours ago
Off topic, but you're not really running this command as root, are you? That
#
prompt makes my eye twitch.– David Conrad
12 hours ago
Off topic, but you're not really running this command as root, are you? That
#
prompt makes my eye twitch.– David Conrad
12 hours ago
Possible duplicate of Remove comments in a C file
– MCCCS
12 hours ago
Possible duplicate of Remove comments in a C file
– MCCCS
12 hours ago
add a comment |
4 Answers
4
active
oldest
votes
Sed has a d
command for deleting whole lines - it can also take an arbitrary (non /
) delimiter, however it needs to be escaped with on first use. So you could do something like
$ sed -e '#^// characteristic_comment_to_delete$#d' -e 's#// characteristic_comment_to_delete.*##' file
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
to first delete lines that consist entirely of // characteristic_comment_to_delete
, then substitute any remaining occurrences.
(I changed your &
to #
to avoid confusion with the sed &
replacement operator).
add a comment |
With GNU sed
:
sed 's|s*// characteristic_comment_to_delete.*||;T;/./!d'
T
is a GNU extension that branches off unless the previous s
substitution was successful. So if no comment was removed, we branch off, and the next /./!d
(which deletes the line unless it contains at least one character) is skipped.
Standard equivalent:
sed '/[[:space:]]*// characteristic_comment_to_delete.*/{s///;/./!d;}'
Or:
sed 's|[[:space:]]*// characteristic_comment_to_delete.*||
t 1
b
:1
/./!d'
Both suppress empty lines only if the substitution was successful.
add a comment |
If you accept an AWK solution:
awk -F "[ ]*//[ ]*characteristic_comment_to_delete.*" '$1 != "" { print $1; }' some_file.cpp
Note: The pattern contains a space and a TAB between the brackets [ ]
.
This solution does not correctly handle string literals containing the comment pattern, e.g.char text = "// characteristic_comment_to_delete bla bla";
add a comment |
Demonstrating storing the comment in a shell variable, and escaping the slash characters with shell parameter expansion. Otherwise, same as steeldriver's answer.
$ comment='// characteristic_comment_to_delete'
$ sed -e "/^[[:blank:]]*${comment////\/}/d" -e "s/${comment////\/}.*//" file
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
add a comment |
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4 Answers
4
active
oldest
votes
4 Answers
4
active
oldest
votes
active
oldest
votes
active
oldest
votes
Sed has a d
command for deleting whole lines - it can also take an arbitrary (non /
) delimiter, however it needs to be escaped with on first use. So you could do something like
$ sed -e '#^// characteristic_comment_to_delete$#d' -e 's#// characteristic_comment_to_delete.*##' file
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
to first delete lines that consist entirely of // characteristic_comment_to_delete
, then substitute any remaining occurrences.
(I changed your &
to #
to avoid confusion with the sed &
replacement operator).
add a comment |
Sed has a d
command for deleting whole lines - it can also take an arbitrary (non /
) delimiter, however it needs to be escaped with on first use. So you could do something like
$ sed -e '#^// characteristic_comment_to_delete$#d' -e 's#// characteristic_comment_to_delete.*##' file
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
to first delete lines that consist entirely of // characteristic_comment_to_delete
, then substitute any remaining occurrences.
(I changed your &
to #
to avoid confusion with the sed &
replacement operator).
add a comment |
Sed has a d
command for deleting whole lines - it can also take an arbitrary (non /
) delimiter, however it needs to be escaped with on first use. So you could do something like
$ sed -e '#^// characteristic_comment_to_delete$#d' -e 's#// characteristic_comment_to_delete.*##' file
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
to first delete lines that consist entirely of // characteristic_comment_to_delete
, then substitute any remaining occurrences.
(I changed your &
to #
to avoid confusion with the sed &
replacement operator).
Sed has a d
command for deleting whole lines - it can also take an arbitrary (non /
) delimiter, however it needs to be escaped with on first use. So you could do something like
$ sed -e '#^// characteristic_comment_to_delete$#d' -e 's#// characteristic_comment_to_delete.*##' file
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
to first delete lines that consist entirely of // characteristic_comment_to_delete
, then substitute any remaining occurrences.
(I changed your &
to #
to avoid confusion with the sed &
replacement operator).
answered 17 hours ago
steeldriversteeldriver
36.4k35286
36.4k35286
add a comment |
add a comment |
With GNU sed
:
sed 's|s*// characteristic_comment_to_delete.*||;T;/./!d'
T
is a GNU extension that branches off unless the previous s
substitution was successful. So if no comment was removed, we branch off, and the next /./!d
(which deletes the line unless it contains at least one character) is skipped.
Standard equivalent:
sed '/[[:space:]]*// characteristic_comment_to_delete.*/{s///;/./!d;}'
Or:
sed 's|[[:space:]]*// characteristic_comment_to_delete.*||
t 1
b
:1
/./!d'
Both suppress empty lines only if the substitution was successful.
add a comment |
With GNU sed
:
sed 's|s*// characteristic_comment_to_delete.*||;T;/./!d'
T
is a GNU extension that branches off unless the previous s
substitution was successful. So if no comment was removed, we branch off, and the next /./!d
(which deletes the line unless it contains at least one character) is skipped.
Standard equivalent:
sed '/[[:space:]]*// characteristic_comment_to_delete.*/{s///;/./!d;}'
Or:
sed 's|[[:space:]]*// characteristic_comment_to_delete.*||
t 1
b
:1
/./!d'
Both suppress empty lines only if the substitution was successful.
add a comment |
With GNU sed
:
sed 's|s*// characteristic_comment_to_delete.*||;T;/./!d'
T
is a GNU extension that branches off unless the previous s
substitution was successful. So if no comment was removed, we branch off, and the next /./!d
(which deletes the line unless it contains at least one character) is skipped.
Standard equivalent:
sed '/[[:space:]]*// characteristic_comment_to_delete.*/{s///;/./!d;}'
Or:
sed 's|[[:space:]]*// characteristic_comment_to_delete.*||
t 1
b
:1
/./!d'
Both suppress empty lines only if the substitution was successful.
With GNU sed
:
sed 's|s*// characteristic_comment_to_delete.*||;T;/./!d'
T
is a GNU extension that branches off unless the previous s
substitution was successful. So if no comment was removed, we branch off, and the next /./!d
(which deletes the line unless it contains at least one character) is skipped.
Standard equivalent:
sed '/[[:space:]]*// characteristic_comment_to_delete.*/{s///;/./!d;}'
Or:
sed 's|[[:space:]]*// characteristic_comment_to_delete.*||
t 1
b
:1
/./!d'
Both suppress empty lines only if the substitution was successful.
edited 12 hours ago
answered 15 hours ago
Stéphane ChazelasStéphane Chazelas
308k57581939
308k57581939
add a comment |
add a comment |
If you accept an AWK solution:
awk -F "[ ]*//[ ]*characteristic_comment_to_delete.*" '$1 != "" { print $1; }' some_file.cpp
Note: The pattern contains a space and a TAB between the brackets [ ]
.
This solution does not correctly handle string literals containing the comment pattern, e.g.char text = "// characteristic_comment_to_delete bla bla";
add a comment |
If you accept an AWK solution:
awk -F "[ ]*//[ ]*characteristic_comment_to_delete.*" '$1 != "" { print $1; }' some_file.cpp
Note: The pattern contains a space and a TAB between the brackets [ ]
.
This solution does not correctly handle string literals containing the comment pattern, e.g.char text = "// characteristic_comment_to_delete bla bla";
add a comment |
If you accept an AWK solution:
awk -F "[ ]*//[ ]*characteristic_comment_to_delete.*" '$1 != "" { print $1; }' some_file.cpp
Note: The pattern contains a space and a TAB between the brackets [ ]
.
This solution does not correctly handle string literals containing the comment pattern, e.g.char text = "// characteristic_comment_to_delete bla bla";
If you accept an AWK solution:
awk -F "[ ]*//[ ]*characteristic_comment_to_delete.*" '$1 != "" { print $1; }' some_file.cpp
Note: The pattern contains a space and a TAB between the brackets [ ]
.
This solution does not correctly handle string literals containing the comment pattern, e.g.char text = "// characteristic_comment_to_delete bla bla";
answered 17 hours ago
BodoBodo
1,780212
1,780212
add a comment |
add a comment |
Demonstrating storing the comment in a shell variable, and escaping the slash characters with shell parameter expansion. Otherwise, same as steeldriver's answer.
$ comment='// characteristic_comment_to_delete'
$ sed -e "/^[[:blank:]]*${comment////\/}/d" -e "s/${comment////\/}.*//" file
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
add a comment |
Demonstrating storing the comment in a shell variable, and escaping the slash characters with shell parameter expansion. Otherwise, same as steeldriver's answer.
$ comment='// characteristic_comment_to_delete'
$ sed -e "/^[[:blank:]]*${comment////\/}/d" -e "s/${comment////\/}.*//" file
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
add a comment |
Demonstrating storing the comment in a shell variable, and escaping the slash characters with shell parameter expansion. Otherwise, same as steeldriver's answer.
$ comment='// characteristic_comment_to_delete'
$ sed -e "/^[[:blank:]]*${comment////\/}/d" -e "s/${comment////\/}.*//" file
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
Demonstrating storing the comment in a shell variable, and escaping the slash characters with shell parameter expansion. Otherwise, same as steeldriver's answer.
$ comment='// characteristic_comment_to_delete'
$ sed -e "/^[[:blank:]]*${comment////\/}/d" -e "s/${comment////\/}.*//" file
some_code
some_more_code // another_comment
another_line_with_code
even_more_code
answered 13 hours ago
glenn jackmanglenn jackman
52.1k572112
52.1k572112
add a comment |
add a comment |
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@jimmij, the OP doesn't want to remove all comments, only
// characteristic_comment_to_delete
– Stéphane Chazelas
15 hours ago
For C-style comments, How can I delete all characters falling under /* .... */ including /* & */? would be a closer match.
– Stéphane Chazelas
15 hours ago
Off topic, but you're not really running this command as root, are you? That
#
prompt makes my eye twitch.– David Conrad
12 hours ago
Possible duplicate of Remove comments in a C file
– MCCCS
12 hours ago