This is a strange problem. I have a batch file where I have two arguments. I wish to check the first three characters of each. The first will substring fine, but the second will not. Here is an example:
SET FIRST_ARG=%1
SET SECOND_ARG=%2
ECHO first argument is %FIRST_ARG%
ECHO first substring is %FIRST_ARG :~1,3%
ECHO second argument is %SECOND_ARG%
ECHO second substring is %SECOND_ARG :~1,3%
The first two ECHO statements work fine and display my strings as they should. The ECHO statement "ECHO second argument is" shows the second argument as it should, but the last line that says "ECHO second substring is" returns nothing.
Have I missed something?
Thanks for any help.
Rob
Your issue is the space preceding the colons :. Using %FIRST_ARG:~1,3% and %SECOND_ARG:~1,3% should fix your issue.
Related
I'm looking for a bit of help here. I'm a complete newbie!
I need to look in a file for a code matching the pattern A00000_00_A and append a count to it, so the first time it appears it is replaced with A00000_00_A_001, second time A00000_00_A_002 etc. The output needs to be written back to the same file. Each file only contains 1 code, but it appears multiple times.
After some digging I have found-
perl -pi -e 's/Q\d{4,5}'_'\d{2}_./$&.'_'.++$A /ge' /users/documents/*.xml
but the issue is the counter does not reset in each file.
That is, the output of the first file is say Q00390_01_A_1 to Q00390_01_A_7, while the second file is Q00391_01_A_8 to Q00391_01_A_10.
What I want is Q00390_01_A_1 to Q00390_01_A_7 in the first file and Q00391_01_A_1 to Q00391_01_A_2 in the second.
Does anyone have any idea on how to edit the above code to make it do that? I'm a total newbie so ideally an edit to what I have would be brilliant. Thanks
cd /users/documents/
for f in *.xml;do
perl -pi -e 's/facs=.(Q|M)\d{4,5}_\d{2}_\w/$&._.sprintf("%04d",++$A) /ge' $f
done
This matches the string facs= and any character, then "Q" or "M" followed by either four or five digits, then an underscore, then two digits, another underscore, and a word character. The entire match is then concatenated with an underscore and the value of $A zero padded to four digits.
Following one example of the book << Learning the Bash Shell >> (O'Reilly),
pathname="/home/cam/book/long.file.name"
echo ${pathname##/*/}
echo ${pathname#/*/}
The expected result should be long.file.name, since ## remove the longest prefix which matches the patter /*/.
However, when I put these three lines inside a script file and run it inside bash, there is no result displayed. But type in these two lines one by one works and shows the expected result.
I wonder if there is any setting related to usage of this operator ## inside executable script.
(Using ubuntu\trusty64 within vagrant.)
Thanks.
UPDATE
The code works fine, the other part of the code affects the results.
In Addition
${path##*/} is a better choice as equivalent to basename command.
Though echo ${pathname##/*/} works fine for me but IMHO you should try following.
echo ${pathname##*/}
Which means you are saying bash with help of regex to remove/substitute everything from starting till last occurrence of / with NULL.
I am having issues with this script taking using the whitespace from my file that contains a list of words with each word on a separate line, I have double check and after each word there is a simple (return) no space yet the script is still calculating with whitespace
ok at that hash then type in:
"hello
"
So hello followed by enter to start a new line. Look at that hash value
That is what I am getting a hash value that is a sting + the enter. As a result my script isnt working the way it is supposed to. Can anyone help.
echo outputs with enter
You can use
echo -n "$test2" | sha256sum
this is my first stackoverflow question, regarding bash scripting. I am a beginner in this language, so be kind with me.
I am trying to write a comparison script. I tried to store all the outputs into variables, but only the last one is stored.
Example code:
me:1234567
you:2345678
us:3456789
My code:
#!bin/bash
while read -r forName forNumber
do
aName="$forName"
echo "$aName"
aNumber="$forNumber"
echo "$aNumber"
done < "exampleCodeFile.txt"
echo "$aNumber"
For the first time, everything will be printed out fine. However, the second echo will only print out "3456789", but not all the numbers again. Same with $aName. This is a problem because i have another file, which i stored a bunch of numbers to compare $aNumber with, using the same method listed above, called $aMatcher, consisting:
aMatcher:
1234567
2345678
3456789
So if i tried to run a comparison:
if [ "$aNumber" == "$aMatcher" ]; then
echo "match found!"
fi
Expected output (with bash -x "scriptname"):
'['1234567 == 1234567']'
echo "match found!"
Actual output (with bash -x "scriptname"):
'['3456789 == 3456789']'
echo "match found!"
Of course my end product would wish to list out all the matches, but i wish to solve my current issue before attempting anything else. Thanks!
When you run your following code
aNumber="$forNumber"
You are over-writing the variable $aNumber for every line of the file exampleCodeFile.txt rather than appending.
If you really want the values to be appended, change the above line to
aNumber="$aNumber $forNumber"
And while matching with $aMatcher, you again have to use a for/while loop to iterate through every value in $aNumber and $aMatcher.
Today, I wanted to test if filenames can contain commas and stumbled upon something else while opening cmd and trying these three tests:
echo a,b>a
This works as supposed (writes a,b to the file named a)
echo a>a,b
Does just the same! What happens here gets a bit clearer with the third test:
echo a>file,b this is a test
This will create a file named file containing a,b this is a test.
Now, three questions arise for me:
What is the explanation for this? If someone asked me, I would've guessed the comma separates commands or filenames, e.g. I would've expected the second test to create two files named a and b.
Is this behaviour documented somewhere?
Is it a cmd specific Windows extension or has it been like this since good old DOS times?
It's expected behaviour as ,;=<space><tab> are delimiters for parameters.
If you put the code into a batch file without echo OFF you will see
test.bat
echo a,b>a
echo a>a,b
echo a>file,b this is a test
Output
C:\temp>test.bat
C:\temp>echo a,b 1>a
C:\temp>echo a,b 1>a
C:\temp>echo a,b this is a test 1>file
After a redirection, only the next token is relevant, the rest is part of the normal line content.
It's unimportant where the redirection occurs in a line.
But there is the rule that when more than one redirection exists for the same stream, the last one will win.
> file.txt echo hello> nul world > con
This will result in hello world at the console.
Btw. There is still an obscure behaviour with redirection and lines extended by carets (multilines).
echo one two three^
four
Result: one two three four
But
echo one two >con three^
four
Result: one two four
The comma is a standard delimiter in batch as well as ; <space> = <tab> and everything after the comma is taken as another parameter to echo and only one parameter is taken for the redirection. You can try to enclose a,b in quotes and this should change the behaviour of the output and produce a,b file. You can also escape the delimiters with ^ - echo a>a^,b
You can try also echo a>a=b - it will be the same.