I want to reduce this down to one line:
item=${_menu_sel_value/M--/}
item=${item/-M-/}
item=${item/D--/}
item=${item/-D-/}
item=${item/??-/}
Here is a test sample. User chooses one of the following from a shell menu and their choice is passed into bash script code above (so, only need to match ONE of the possibilities):
-D-branch.sh
M--cfg/aliases.cfg
-M-functions/0300.menu.sh
M--git_aliases.sh
??-add.sh
Is it possible?
I tried something like:
item=${_menu_sel_value/^[M\-]/}
But it didn't work.
I think this is what you are looking for.
shopt -s extglob
item=${_menu_sel_value/#(M--|-M-|D--|-D-|\?\?-)/}
The pattern #(a|b|c) matches any one of the patterns a, b, or c. Note the need to escape the ?, as it is a wildcard that matches any single character in a pattern.
If you know that you'll always have the first three characters that need to be stripped off, you can just use a substring operation:
item=${_menu_sel_value:3}
Related
For a gradle script, I am composing strings that will be used as command line for a subsequent gradle Test-task. One of the strings is the user's password, which eventually will be passed to the called (exec'ed) "java ..." call using the JVM's -D option, e.g. -Dpassword=foobar.
What complicates things here is, that this password can/should of course contain special characters, that may interfere with the use of the string as command line. In other words: I need to escape special characters (which is OS-specific). :-(
Now to my actual question:
I want to use the String.replaceAll method, i.e. replaceAll(list_of_special characters, EscapeCharacter + Ref_to_matched_character),
e.g. simplified something like replaceAll("[#$%^&]", "^$1")
'^' meaning the escape character and '$1' meaning the matched character here.
Is that possible, i.e. can one refer to the matched pattern in the second argument of replaceAll?
Is that possible, i.e. can one refer to the matched pattern in the second argument of replaceAll?
yes, it's possible
'a#b$c'.replaceAll('([#$%^&])', '^$1')
returns
a^#b^$c
Thanks for the responses and the reviews improving readability. Meanwhile I got my expression working. For those interested:
// handles gthe following: `~!##$%^&*()_+-={}|[]\:;"'<>?,./
escaped = original.replaceAll('[~!##\\$\\%\\^\\&\\*\\(\\)_\\+-={}\\|\\[\\]\\\\:;\"\\\'<>\\?,\\./]', '^$0') // for Windows - cmd.exe
I would like to implement a small subset of siri/cortana like features in command line.
For e.g.
$ What is the sum of 100 and 1000
> Response: 1100
$ What is the product of 10 and 12
> Response: 120
The questions are predefined regular expressions. It needs to call the matching function in ruby.
Pattern: What is the sum of (\d)+ and (\d)+
Ruby method to call: sum(a,b)
Any pointers/suggestion is appreciated.
That sounds exactly like cucumber, maybe take a look and see if you can just use their classes to hack something together :) ?
You could do something like the following:
question = gets.chomp
/\A.*(sum |product |quotient |difference )\D+([0-9]+)\D+([0-9]+).*\z/.match question
send($1, $2.to_i, $3.to_i)
Quick explanation for anyone that may be new to matching in Ruby:
This gets a line of input from the command line and scans it for a function name (i.e. sum, product, etc) followed by a space and potentially some non-digit characters. Then, it looks for a first number (similarly followed by a space and 0 or more non-digit characters) and a second number followed by nothing or anything. The parentheses determine what gets assigned to the variables preceded by a $, i.e. the substring that matches the contents of the first set of parentheses gets assigned to $1.
Next, it calls the method whose name is the value of $1 with the arguments (casted to integers) found in $2 and $3.
Obviously, this isn't generalized at all--you're putting the method names in the regex, and it's taking a fixed number of arguments--but it'll hopefully be useful for getting you on the right track.
I want to parse the following word in shell script
VERSION=METER1.2.1
Here i want to split it as two words as
WORD1=METER
WORD2=1.2.1
Let me help how to parse it?
Far more efficient than using external tools such is sed is bash's built-in parameter expansion support. For instance, if you want the name variable to contain everything until the first number, and the numbers variable to contain everything after the last alpha character:
version=METER1.2.1
name=${version%%[0-9]*}
numbers=${version##*[[:alpha:]]}
To understand this, see the BashFAQ entry on string manipulation in general, or the BashFAQ entry on parameter expansion in particular.
I am trying to write a bash script that uses sed to modify lines in a config file not containing a specific string. To illustrate by example, I could have ...
/some/file/path1 ipAddress1/subnetMask(rw,sync,no_root_squash)
/some/file/path2 ipAddress1/subnetMask(rw,sync,no_root_squash,anonuid=-1)
/some/file/path3 ipAddress2/subnetMask(rw,sync,no_root_squash,anonuid=0)
/some/file/path4 ipAddress2/subnetMask(rw,sync,no_root_squash,anongid=-1)
/some/file/path5 ipAddress2/subnetMask(rw,sync,no_root_squash,anonuid=-1,anongid=-1)
And I want every line's parenthetical list to be changed such that it contains strings anonuid=-1 and anongid=-1 within its parentheses ...
/some/file/path1 ipAddress1/subnetMask(rw,sync,no_root_squash,anonuid=-1,anongid=-1)
/some/file/path2 ipAddress1/subnetMask(rw,sync,no_root_squash,anonuid=-1,anongid=-1)
/some/file/path3 ipAddress2/subnetMask(rw,sync,no_root_squash,anonuid=-1,anongid=-1)
/some/file/path4 ipAddress2/subnetMask(rw,sync,no_root_squash,anongid=-1,anonuid=-1)
/some/file/path5 ipAddress2/subnetMask(rw,sync,no_root_squash,anonuid=-1,anongid=-1)
As can be seen from the example, both anonuid and anongid may already exist within the parentheses, but it is possible that the original parenthetical list has one string but not the other (lines 2, 3, and 4), the list has neither (line 1), the list has both already set properly (line 5), or even one or both of them are set incorrectly (line 3). When either anonuid or anongid is set to a value other than -1, it must be changed to the proper value of -1 (line 3).
What would be the best way to edit my config file using sed such that anonuid=-1 and anongid=-1 is contained in each line's parenthetical list, separated by a comma delimiter of course?
I think this does what you want:
sed -e '/anonuid/{s/anonuid=[-0-9]*/anonuid=-1/;b gid;};s/)$/,anonuid=-1)/;:gid;/anongid/{s/anongid=[-0-9]*/anongid=-1/;b;};s/)$/,anongid=-1)/'
Basically, it has two nearly identical parts with the first dealing with anonuid and the second anongid, each with a bit of logic to decide if it needs to replace or add the appropriate values. (It doesn't bother to check if the value is already correct, that would just complicate things while not changing the results.)
You can use sed to specify the lines you are interested in:
$ sed '/anonuid=..*,anongid=..*)$/!p' $file
The above will print (p) all lines that don't match the regular expression between the two slashes. I negated the expression by using the !. This way, you're not matching lines with both anaonuid and anongid in them.
Now, you can work on the non-matching lines and editing those with the sed s command:
$ sed '/anonuid=..*,anongid=..*)$/!s/from/to/`
The manipulation might be fairly complex, and you might be passing multiple sed commands to get everything just right.
However, if the string no_root_squash appear in each line you want to change, why not take the simple way out:
$ sed 's/no_root_squash.*$/no_root_squash,anonuid=-1,anongid=-1)/' $file
This is looking for that no_root_squash string, and replacing everything from that string to the end of the line with the text you want. Are there lines you are touching that don't need to be edited? Yes, but you're not really changing those lines. You're basically substituting /no_root_squash,anonuid=-1,anongid=-1) with the same /no_root_squash,anonuid=-1,anongid=-1).
This may be faster even though it's replacing text that doesn't need replacing because there's less processing going on. Plus, it's easier to understand and support in the future.
Response
Thanks David! Yeah I was considering going that route, but I didn't want to rely 100% on every line containing no_root_squash. My current config file only ends in that string, but I'm just not 100% sure that won't potentially be different in the field. Do you think there would be a way to change that so it just overwrites from the end of the last string not containing anonuid=-1 or anongid=-1 onward?
What can you guarantee will be in each line?
You might be able to do a capture group:
sed 's/\(sync,[^,)]*\).*/\1,anonuid=-1,anongid=-1)/' $file
The \(..\) is a capture group. It basically captures that portion of the matching regular expression, and then allows you to reuse it via the \1. I'm capturing from the word sync to a group of characters not including a comma or a closing parentheses. Then, I'm appending the capture group, a comma, and your anon uid and gid.
Will that work?
Maybe I am oversimplifying:
sed 's/anonuid=[-0-9]*[^)]//g;s/anongid=[-0-9]*[^)]//g;s/[)]/anonuid=-1,anongid=-1)/g' test.txt > test3.txt
This just drops any current instance of anonuid or anongid and adds the string
"anonuid=-1,anongid=-1" into the parentheses
How should I use 'sed' command to find and replace the given word/words/sentence without considering any of them as the special character?
In other words hot to treat find and replace parameters as the plain text.
In following example I want to replace 'sagar' with '+sagar' then I have to give following command
sed "s/sagar/\\+sagar#g"
I know that \ should be escaped with another \ ,but I can't do this manipulation.
As there are so many special characters and theie combinations.
I am going to take find and replace parameters as input from user screen.
I want to execute the sed from c# code.
Simply, I do not want regular expression of sed to use. I want my command text to be treated as plain text?
Is this possible?
If so how can I do it?
While there may be sed versions that have an option like --noregex_matching, most of them don't have that option. Because you're getting the search and replace input by prompting a user, you're best bet is to scan the user input strings for reg-exp special characters and escape them as appropriate.
Also, will your users expect for example, their all caps search input to correctly match and replace a lower or mixed case string? In that case, recall that you could rewrite their target string as [Ss][Aa][Gg][Aa][Rr], and replace with +Sagar.
Note that there are far fewer regex characters used on the replacement side, with '&' meaning "complete string that was matched", and then the numbered replacment groups, like \1,\2,.... Given users that have no knowledge or expectation that they can use such characters, the likelyhood of them using is \1 in their required substitution is pretty low. More likely they may have a valid use for &, so you'll have to scan (at least) for that and replace with \&. In a basic sed, that's about it. (There may be others in the latest gnu seds, or some of the seds that have the genesis as PC tools).
For a replacement string, you shouldn't have to escape the + char at all. Probably yes for \. Again, you can scan your user's "naive" input, and add escape chars as need.
Finally if you're doing this for a "package" that will be distributed, and you'll be relying on the users' version of sed, beware that there are many versions of sed floating around, some that have their roots in Unix/Linux, and others, particularly of super-sed, that (I'm pretty sure) got started as PC-standalones and has a very different feature set.
IHTH.