antlr4 grammar match any character question - antlr4

I think .*? can match any characters except \n, but follow can not parse '{' and '}'

Inside a parser rule, the . matches any token, not any character. Change the rule into a lexer rule instead:
HeadDesc : '<?' .*? '?>';
And then the . will also match line breaks.

Related

sed command error "sed: bad option in substitution expression" [duplicate]

I am using sed in a shell script to edit filesystem path names. Suppose I want to replace
/foo/bar
with
/baz/qux
However, sed's s/// command uses the forward slash / as the delimiter. If I do that, I see an error message emitted, like:
▶ sed 's//foo/bar//baz/qux//' FILE
sed: 1: "s//foo/bar//baz/qux//": bad flag in substitute command: 'b'
Similarly, sometimes I want to select line ranges, such as the lines between a pattern foo/bar and baz/qux. Again, I can't do this:
▶ sed '/foo/bar/,/baz/qux/d' FILE
sed: 1: "/foo/bar/,/baz/qux/d": undefined label 'ar/,/baz/qux/d'
What can I do?
You can use an alternative regex delimiter as a search pattern by backslashing it:
sed '\,some/path,d'
And just use it as is for the s command:
sed 's,some/path,other/path,'
You probably want to protect other metacharacters, though; this is a good place to use Perl and quotemeta, or equivalents in other scripting languages.
From man sed:
/regexp/
Match lines matching the regular expression regexp.
\cregexpc
Match lines matching the regular expression regexp. The c may be any character other than backslash or newline.
s/regular expression/replacement/flags
Substitute the replacement string for the first instance of the regular expression in the pattern space. Any character other than backslash or newline can be used instead of a slash to delimit the RE and the replacement. Within the RE and the replacement, the RE delimiter itself can be used as a literal character if it is preceded by a backslash.
Perhaps the closest to a standard, the POSIX/IEEE Open Group Base Specification says:
[2addr] s/BRE/replacement/flags
Substitute the replacement string for instances of the BRE in the
pattern space. Any character other than backslash or newline can
be used instead of a slash to delimit the BRE and the replacement.
Within the BRE and the replacement, the BRE delimiter itself can be
used as a literal character if it is preceded by a backslash."
When there is a slash / in theoriginal-string or the replacement-string, we need to escape it using \. The following command is work in ubuntu 16.04(sed 4.2.2).
sed 's/\/foo\/bar/\/baz\/qux/' file

Replace the word with "\" using sed command fails? [duplicate]

I am using sed in a shell script to edit filesystem path names. Suppose I want to replace
/foo/bar
with
/baz/qux
However, sed's s/// command uses the forward slash / as the delimiter. If I do that, I see an error message emitted, like:
▶ sed 's//foo/bar//baz/qux//' FILE
sed: 1: "s//foo/bar//baz/qux//": bad flag in substitute command: 'b'
Similarly, sometimes I want to select line ranges, such as the lines between a pattern foo/bar and baz/qux. Again, I can't do this:
▶ sed '/foo/bar/,/baz/qux/d' FILE
sed: 1: "/foo/bar/,/baz/qux/d": undefined label 'ar/,/baz/qux/d'
What can I do?
You can use an alternative regex delimiter as a search pattern by backslashing it:
sed '\,some/path,d'
And just use it as is for the s command:
sed 's,some/path,other/path,'
You probably want to protect other metacharacters, though; this is a good place to use Perl and quotemeta, or equivalents in other scripting languages.
From man sed:
/regexp/
Match lines matching the regular expression regexp.
\cregexpc
Match lines matching the regular expression regexp. The c may be any character other than backslash or newline.
s/regular expression/replacement/flags
Substitute the replacement string for the first instance of the regular expression in the pattern space. Any character other than backslash or newline can be used instead of a slash to delimit the RE and the replacement. Within the RE and the replacement, the RE delimiter itself can be used as a literal character if it is preceded by a backslash.
Perhaps the closest to a standard, the POSIX/IEEE Open Group Base Specification says:
[2addr] s/BRE/replacement/flags
Substitute the replacement string for instances of the BRE in the
pattern space. Any character other than backslash or newline can
be used instead of a slash to delimit the BRE and the replacement.
Within the BRE and the replacement, the BRE delimiter itself can be
used as a literal character if it is preceded by a backslash."
When there is a slash / in theoriginal-string or the replacement-string, we need to escape it using \. The following command is work in ubuntu 16.04(sed 4.2.2).
sed 's/\/foo\/bar/\/baz\/qux/' file

sed replace paths in all files on system [duplicate]

I am using sed in a shell script to edit filesystem path names. Suppose I want to replace
/foo/bar
with
/baz/qux
However, sed's s/// command uses the forward slash / as the delimiter. If I do that, I see an error message emitted, like:
▶ sed 's//foo/bar//baz/qux//' FILE
sed: 1: "s//foo/bar//baz/qux//": bad flag in substitute command: 'b'
Similarly, sometimes I want to select line ranges, such as the lines between a pattern foo/bar and baz/qux. Again, I can't do this:
▶ sed '/foo/bar/,/baz/qux/d' FILE
sed: 1: "/foo/bar/,/baz/qux/d": undefined label 'ar/,/baz/qux/d'
What can I do?
You can use an alternative regex delimiter as a search pattern by backslashing it:
sed '\,some/path,d'
And just use it as is for the s command:
sed 's,some/path,other/path,'
You probably want to protect other metacharacters, though; this is a good place to use Perl and quotemeta, or equivalents in other scripting languages.
From man sed:
/regexp/
Match lines matching the regular expression regexp.
\cregexpc
Match lines matching the regular expression regexp. The c may be any character other than backslash or newline.
s/regular expression/replacement/flags
Substitute the replacement string for the first instance of the regular expression in the pattern space. Any character other than backslash or newline can be used instead of a slash to delimit the RE and the replacement. Within the RE and the replacement, the RE delimiter itself can be used as a literal character if it is preceded by a backslash.
Perhaps the closest to a standard, the POSIX/IEEE Open Group Base Specification says:
[2addr] s/BRE/replacement/flags
Substitute the replacement string for instances of the BRE in the
pattern space. Any character other than backslash or newline can
be used instead of a slash to delimit the BRE and the replacement.
Within the BRE and the replacement, the BRE delimiter itself can be
used as a literal character if it is preceded by a backslash."
When there is a slash / in theoriginal-string or the replacement-string, we need to escape it using \. The following command is work in ubuntu 16.04(sed 4.2.2).
sed 's/\/foo\/bar/\/baz\/qux/' file

How i can solve shell command error ?

i'm using shell coding to change a file code by "sed" commnand.
sed -i -- 's/0 * * * * /home/flash/eAn/etl/repcompre.sh start/#0 * * * * /home/fla/eAn/etl/repcompr.sh start/g' '/tmp/.tab.tmp'
its not working i have this error :
sed: -e expression #1, char 19: unknown option to `s'
Thanks
From info sed, section "The 's' command":
The syntax of the 's' command is 's/REGEXP/REPLACEMENT/FLAGS'.
[…]
The '/' characters may be uniformly replaced by any other single
character within any given 's' command. The '/' character (or whatever
other character is used in its stead) can appear in the REGEXP or
REPLACEMENT only if it is preceded by a '\' character
In other words, whenever your REGEXP or REPLACEMENT contains slashes you have to either
replace the slashes between and around REGEXP and REPLACEMENT with another character like # or % or
prefix each slash in REGEXP and REPLACEMENT with a backslash (\) character.

sed pattern command

So I have this sed command applied on $1 wich is a file
what I'd like to know is how sed evaluates all the slash, backslash
succession and what does any character in the pattern mean
sed '/^\/\*/d/.*\*\//d' $1
as far as I know
'/^ ....../d'
deletes some pattern at the begining of line (considering the second d)
-what does the first d stand for, what about the dot and the / or /\ (unescape chars?)
could please someone explain this to me please ?
This is actually two sed commands back to back:
/^\/\*/d
/.*\*\//d
^ matches start of line, \/ matches a literal forward-slash, \* matches a literal asterisk. (Since forward-slash and asterisk are "meta-characters", they need to be escaped with a backslash to match literally.)
.* matches any sequence of characters, \* matches a literal asterisk again, \/ matches a literal slash again.
Put it all together, and what this does is to delete C-style comments, but only if they appear at the start of a line:
/* This will go away */This will stay

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