I am new to Bash, but hoping this is simple to do. I have the following couple lines of code:
LOCATION='C:\\proj\\myproject\\node_modules\\protractor\\node_modules\\webdriver-manager\\selenium\\chromedriver_2.29.exe'
FILENAME=${LOCATION}
How do I parse past all the backslashes, go to the end of the path, extract the file name and assign it to $FILENAME (in this case 'chromedriver_2.29.exe') ?
This should do the trick:
FILENAME=${LOCATION##*'\\'}
See details on parameter expansion in Bash here.
Related
I'm trying to convert TXT files into pipe-delimited text files.
Let's say I have a file called sample.csv:
aaa",bbb"ccc,"ddd,eee",fff,"ggg,hhh,iii","jjj kkk","lll"" mmm","nnn"ooo,ppp"qqq",rrr" sss,"ttt,""uuu",Z
I'd like to convert this into an output that looks like this:
aaa"|bbb"ccc|ddd,eee|fff|ggg,hhh,iii|jjj kkk|lll" mmm|"nnn"ooo|ppp"qqq"|rrr" sss|ttt,"uuu|Z
Now after tons of searching, I have come the closest using this sed command:
sed -r 's/""/\v/g;s/("([^"]+)")?,/\2\|/g;s/"([^"]+)"$/\1/;s/\v/"/g'
However, the output that I received was:
aaa"|bbb"ccc|ddd,eee|fff|ggg,hhh,iii|jjj kkk|lll" mmm|"nnn"ooo|pppqqq|rrr" sss|ttt,"uuu|Z
Where the expected for the 9th column should have been ppp"qqq" but the result removed the double quotes and what I got was pppqqq.
I have been playing around with this for a while, but to no avail.
Any help regarding this would be highly appreciated.
As suggested in comments sed or any other Unix tool is not recommended for this kind of complex CSV string. It is much better to use a dedicated CSV parser like this in PHP:
$s = 'aaa",bbb"ccc,"ddd,eee",fff,"ggg,hhh,iii","jjj kkk","lll"" mmm","nnn"ooo,ppp"qqq",rrr" sss,"ttt,""uuu",Z';
echo implode('|', str_getcsv($s));
aaa"|bbb"ccc|ddd,eee|fff|ggg,hhh,iii|jjj kkk|lll" mmm|nnnooo|ppp"qqq"|rrr" sss|ttt,"uuu|Z
The problem with sample.csv is that it mixes non-quoted fields (containing quotes) with fully quoted fields (that should be treated as such).
You can't have both at the same time. Either all fields are (treated as) unquoted and quotes are preserved, or all fields containing a quote (or separator) are fully quoted and the quotes inside are escaped with another quote.
So, sample.csv should become:
"aaa""","bbb""ccc","ddd,eee",fff,"ggg,hhh,iii","jjj kkk","lll"" mmm","""nnn""ooo","ppp""qqq""","rrr"" sss","ttt,""uuu",Z
to give you the desired result (using a csv parser):
aaa"|bbb"ccc|ddd,eee|fff|ggg,hhh,iii|jjj kkk|lll" mmm|"nnn"ooo|ppp"qqq"|rrr" sss|ttt,"uuu|Z
Have the same problem.
I found right result with https://www.papaparse.com/demo
Here is a FOSS on github. So maybe you can check how it works.
With the source of [ "aaa""","bbb""ccc","ddd,eee",fff,"ggg,hhh,iii","jjj kkk","lll"" mmm","""nnn""ooo","ppp""qqq""","rrr"" sss","ttt,""uuu",Z ]
The result appears in the browser console:
[1]: https://i.stack.imgur.com/OB5OM.png
Before to write, of course I read many other similar cases. Example I used #!/bin/bash instead of #!/bin/sh
I have a very simple script that reads lines from a template file and wants to replace some keywords with real data. Example the string <NAME> will be replaced with a real name. In the example I want to replace it with the word Giuseppe. I tried 2 solutions but they don't work.
#!/bin/bash
#read the template and change variable information
while read LINE
do
sed 'LINE/<NAME>/Giuseppe' #error: sed: -e expression #1, char 2: extra characters after command
${LINE/<NAME>/Giuseppe} #error: WORD(*) command not found
done < template_mail.txt
(*) WORD is the first word found in the line
I am sorry if the question is too basic, but I cannot see the error and the error message is not helping.
EDIT1:
The input file should not be changed, i want to use it for every mail. Every time i read it, i will change with a different name according to the receiver.
EDIT2:
Thanks your answers i am closer to the solution. My example was a simplified case, but i want to change also other data. I want to do multiple substitutions to the same string, but BASH allows me only to make one substitution. In all programming languages i used, i was able to substitute from a string, but BASH makes this very difficult for me. The following lines don't work:
CUSTOM_MAIL=$(sed 's/<NAME>/Giuseppe/' template_mail.txt) # from file it's ok
CUSTOM_MAIL=$(sed 's/<VALUE>/30/' CUSTOM_MAIL) # from variable doesn't work
I want to modify CUSTOM_MAIL a few times in order to include a few real informations.
CUSTOM_MAIL=$(sed 's/<VALUE1>/value1/' template_mail.txt)
${CUSTOM_MAIL/'<VALUE2>'/'value2'}
${CUSTOM_MAIL/'<VALUE3>'/'value3'}
${CUSTOM_MAIL/'<VALUE4>'/'value4'}
What's the way?
No need to do the loop manually. sed command itself runs the expression on each line of provided file:
sed 's/<NAME>/Giuseppe/' template_mail.txt > output_file.txt
You might need g modifier if there are more appearances of the <NAME> string on one line: s/<NAME>/Giuseppe/g
I'm having to code a subversion hook script, and I found a few examples online, mostly python and perl. I found one or two shell scripts (bash) as well. I am confused by a line and am sorry this is so basic a question.
FILTER=".(sh|SH|exe|EXE|bat|BAT)$"
The script later uses this to perform a test, such as (assume EXT=ex):
if [[ "$FILTER" == *"$EXT"* ]]; then blah
My problem is the above test is true. However, I'm not asking you to assist in writing the script, just explaining the initial assignment of FILTER. I don't understand that line.
Editing in a closer example FILTER line. Of course the script, as written does not work, because 'ex' returns true, and not just 'exe'. My problem here is only, however, that I don't understant the layout of the variable assignment itself.
Why is there a period at the beginning? ".(sh..."
Why is there a dollar sign at the end? "...BAT)$"
Why are there pipes between each pattern? "sh|SH|exe"
You probably looking for something as next:
FILTER="\.(sh|SH|exe|EXE|bat|BAT)$"
for EXT
do
if [[ "$EXT" =~ $FILTER ]];
then
echo $EXT extension disallowed
else
echo $EXT is allowed
fi
done
save it to myscript.sh and run it as
myscript.sh bash ba.sh
and will get
bash is allowed
ba.sh extension disallowed
If you don't escape the "dot", e.g. with the FILTER=".(sh|SH|exe|EXE|bat|BAT)$" you will get
bash extension disallowed
ba.sh extension disallowed
What is (of course) wrong.
For the questions:
Why is there a period at the beginning? ".(sh..."
Because you want match .sh (as extension) and not for example bash (without the dot). And therefore the . must be escaped, like \. because the . in regex mean "any character.
Why is there a dollar sign at the end? "...BAT)$"
The $ mean = end of string. You want match file.sh and not file.sh.jpg. The .sh should be at the end of string.
Why are there pipes between each pattern? "sh|SH|exe"
In the rexex, the (...|...|...) construction delimites the "alternatives". As you sure quessed.
You really need read some "regex tutorial" - it is more complicated - and can't be explained in one answer.
Ps: NEVER use UPPERCASE variable names, they can collide with environment variables.
This just assigns a string to FILTER; the contents of that string have no special meaning. When you try to match it against the pattern *ex*, the result is true assuming that the value of $FILTER consists the string ex surrounded by anything on either side. This is true; ex is a substring of exe.
FILTER=".(sh|SH|exe|EXE|bat|BAT)$"
^^
|
+---- here is the "ex" from the pattern.
As I can this is similar to regular expression pattern:
In regular expressions the string start with can be show with ^, similarly in this case . represent seems doing that.
In the bracket you have exact string, which represents what the exact file extensions would be matched, they are 'Or' by using the '|'.
And at the end the expression should only pick the string will '$' or end point and not more than.
I would say that way original author might have looked at it and implemented it.
I'm trying to make a script that will go into a directory and run my own application with each file matching a regular expression, specifically Test[0-9]*.txt.
My input filenames look like this TestXX.txt. Now, I could just use cut and chop off the Test and .txt, but how would I do this if XX wasn't predefined to be two digits? What would I do if I had Test1.txt, ..., Test10.txt? In other words, How would I get the [0-9]* part?
Just so you know, I want to be able to make a OutputXX.txt :)
EDIT:
I have files with filename Test[0-9]*.txt and I want to manipulate the string into Output[0-9]*.txt
Would something like this help?
#!/bin/bash
for f in Test*.txt ;
do
process < $f > ${f/Test/Output}
done
Bash Shell Parameter Expansion
A good tutorial on regexes in bash is here. Summarizing, you need something like:
if [[$filenamein =~ "^Test([0-9]*).txt$"]]; then
filenameout = "Output${BASH_REMATCH[1]}.txt"
and so on. The key is that, when you perform the =~" regex-match, the "sub-matches" to parentheses-enclosed groups in the RE are set in the entries of arrayBASH_REMATCH(the[0]entry is the whole match,1` the first parentheses-enclosed group, etc).
You need to use rounded brackets around the part you want to keep.
i.e. "Test([0-9]*).txt"
The syntax for replacing these bracketed groups varies between programs, but you'll probably find you can use \1 , something like this:
s/Test(0-9*).txt/Output\1.txt/
If you're using a unix shell, then 'sed' might be your best bet for performing the transformation.
http://www.grymoire.com/Unix/Sed.html#uh-4
Hope that helps
for file in Test[0-9]*.txt;
do
num=${file//[^0-9]/}
process $file > "Output${num}.txt"
done
I am writing a shell (bash) script and I'm trying to figure out an easy way to accomplish a simple task.
I have some string in a variable.
I don't know if this is relevant, but it can contain spaces, newlines, because actually this string is the content of a whole text file.
I want to replace the last occurence of a certain substring with something else.
Perhaps I could use a regexp for that, but there are two moments that confuse me:
I need to match from the end, not from the start
the substring that I want to scan for is fixed, not variable.
for truncating at the start: ${var#pattern}
truncating at the end ${var%pattern}
${var/pattern/repl} for general replacement
the patterns are 'filename' style expansion, and the last one can be prefixed with # or % to match only at the start or end (respectively)
it's all in the (long) bash manpage. check the "Parameter Expansion" chapter.
amn expression like this
s/match string here$/new string/
should do the trick - s is for sustitute, / break up the command, and the $ is the end of line marker. You can try this in vi to see if it does what you need.
I would look up the man pages for awk or sed.
Javier's answer is shell specific and won't work in all shells.
The sed answers that MrTelly and epochwolf alluded to are incomplete and should look something like this:
MyString="stuff ttto be edittted"
NewString=`echo $MyString | sed -e 's/\(.*\)ttt\(.*\)/\1xxx\2/'`
The reason this works without having to use the $ to mark the end is that the first '.*' is greedy and will attempt to gather up as much as possible while allowing the rest of the regular expression to be true.
This sed command should work fine in any shell context used.
Usually when I get stuck with Sed I use this page,
http://sed.sourceforge.net/sed1line.txt