All Questions
Tagged with quoting regular-expression
52
questions
3
votes
2
answers
4k
views
Define a variable to awk pattern matching from bash
I am trying to grab 100 lines after the text "time: X" with X in {0,40,80,...,200}. Here is what I have so far:
#!/bin/bash
start=1
end=5
for i in $(seq $start $end);do
j=$(($i*40))
awk '/time: ...
- 31
2
votes
4
answers
6k
views
Why does the grep command ignore the period in the search string?
The command that I am using:
find . -type f -name "*.sql" -exec grep -i -l 'schema_name.' {} +
What I want to search is all the files which contain schema_name..
But the find command is ignoring the ...
- 273
1
vote
1
answer
2k
views
regular expression : with a variable
arrFormat=( jpg jpeg bmp tiff png )
varExtension="jpg"
for elem in "${arrFormat[@]}"
do
echo "${elem}"
# do something on $elem #
done
#for i in $( find -E . -iregex '.*\.($arrFormat)' ) ; do #...
- 163
3
votes
1
answer
3k
views
cshell alias: How to use nested single quotes(') in in cshell alias
I am trying below alias in cshell:
alias sll 'ls -l \!* | grep -oE '[^ ]+$' | paste -s | xargs ls -l'
For this CSH says, Illegal variable name.
If I use \$, alias will be set without any error. But ...
- 155
0
votes
3
answers
838
views
significance behind escaping parentheses in expr match
Can anybody give me the difference between the following two commands in the context of escaping parentheses, or refer some document that would clear my doubt.
string=abcABC123ABCabc
$ echo `expr ...
- 71
1
vote
1
answer
3k
views
What does a backslash represent when searching for decimals
I want to understand what the backslash represents in this command. grep "\.900983" table
I know what the command does, it searches for the 900983 value in table, I'm just not sure of the purpose of ...
- 1,071
3
votes
2
answers
2k
views
How to escape metacharacters for egrep like metaquote from Perl?
Perl has a function called metaquote() to escape all special characters for a regular expression.
Is there an equivalent technique for egrep?
Example: If I am searching for the string abc.def.ghi, I ...
- 687
0
votes
0
answers
358
views
swap strings of text inside vim using regex
I am working with a file where I need to swap "string A" and "String B's" locations simultaneously with a regex inside the vim. Here is an example line of code:
succ_1st=`grep 'resulted in successful ...
- 2,843
4
votes
1
answer
1k
views
Match pattern \\\" using grep
I have a json string inside json. This got encoded multiple times and I ended up with many escape backlashes: \\\".
The much shortened string looks like,
'[{"testId" : "12345", "message": "\\\"the ...
user93868
0
votes
1
answer
264
views
What does "\(\)" stand for in this command: grep("-(mean|std)\(\)", x[,2])
Need to know about the function of \(\) in grep("-(mean|std)\(\)", x[,2])
6
votes
1
answer
678
views
Why can't I escape the braces "]" in sed?
Question: Why can't I escape the "]"?
$ printf "*#$@~\!&*()[]\n"
*#~\!&*()[]
$ printf "*#$@~\!&*()[]\n" | sed 's/[*#$@~!&*()\[\]]//g'
*#~\!&*()
$
- 1,519
1
vote
2
answers
2k
views
How to search parenthesis by ack
I want to search for a parentheis ( using ack, but neither using ( nor \( worked.
The first one ("(") is recognized as a multiple line command.
The second one ("\(") is treated as an invalid regular ...
- 5,265
3
votes
3
answers
703
views
Why awk understand FS="*" but not for FS="-*-"?
I got a test file, its content is:
a -*- b
I used awk 'BEGIN {FS="*"} {print $2}' test, it prints out
- b
Correct! But when I use awk 'BEGIN {FS="-*-"} {print $2}' test, I got:
*
I know that FS ...
- 7,677
1
vote
2
answers
2k
views
Why does regex with \\$\{ work with egrep, but not with sed?
Given a text like this
./RFF_09 -f${FILE} -c${COND}
inside a file, this egrep command will correctly match:
egrep './RFF(.*) (.*)-c\\$\{COND\}' file
but this sed command will not
sed -n "s:'./RFF(...
- 123
1
vote
0
answers
76
views
Take the unknown contents of variable as literal in sed [duplicate]
I have two files: a.patterns contains patterns in a one per line way
"`"
"^"
"<"
"<("
"<)"
"<["
"="
">"
"_;|^+*+?@"
and b.data contains comma separated values.
1,1,0,"*",1
2,1,1,"*",...
- 111