Regular expression woes


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Regular expression woes
# 1  
Old 05-17-2010
Power Regular expression woes

(Continuation of this thread: https://www.unix.com/shell-programmin...n-problem.html)

how would I replace a line that contains only a number, e.g. 6.00, with another number stored in variable $bulksize or $half ?

I guess I don't understand all the parts in this regular expression
'187s/= [^,]*/= %s/\nwq\n'

I know 187 is the line number, the s after that is substitution, and ^, matches a comma in the beginning? Or anything that's not a comma? Not sure what the rest of it means... where can I find a good reference for this?

Thanks!!
# 2  
Old 05-17-2010
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

sed: -e expression #1, char 0: no previous regular expression

Hello All, I'm trying to extract the lines between two consecutive elements of an array from a file. My array looks like: problem_arr=(PRS111 PRS213 PRS234) j=0 while } ] do k=`expr $j + 1` sed -n "/${problem_arr}/,/${problem_arr}/p" problemid.txt ---some operation goes... (11 Replies)
Discussion started by: InduInduIndu
11 Replies

2. Programming

Perl: How to read from a file, do regular expression and then replace the found regular expression

Hi all, How am I read a file, find the match regular expression and overwrite to the same files. open DESTINATION_FILE, "<tmptravl.dat" or die "tmptravl.dat"; open NEW_DESTINATION_FILE, ">new_tmptravl.dat" or die "new_tmptravl.dat"; while (<DESTINATION_FILE>) { # print... (1 Reply)
Discussion started by: jessy83
1 Replies

3. Shell Programming and Scripting

Integer expression expected: with regular expression

CA_RELEASE has a value of 6. I need to check if that this is a numeric value. if not error. source $CA_VERSION_DATA if * ] then echo "CA_RELESE $CA_RELEASE is invalid" exit -1 fi + source /etc/ncgl/ca_version_data ++ CA_PRODUCT_ID=samxts ++ CA_RELEASE=6 ++ CA_WEEK_NO=7 ++... (3 Replies)
Discussion started by: ketkee1985
3 Replies

4. Shell Programming and Scripting

regular expression [^ ]

Hi, Could anybody explain why will evaluate to true for a string that is not null, not empty string, and has at least one non-space char? My understanding is that ^ means exclude all chars inside . So I thought it should mean anything except space. This seems a big mystery to me. (9 Replies)
Discussion started by: iengca
9 Replies

5. Shell Programming and Scripting

Regular expression

Hi I have to extract the first field and the last %field of the following out put.. /home (/abc/def/bhd ) : 522328 total allocated Kb 319448 free allocated Kb ... (2 Replies)
Discussion started by: Harikrishna
2 Replies

6. UNIX for Dummies Questions & Answers

Regular expression help

HI All, I want to list a file with the below format : testfile_nnnnn.xxxx where n and x can be any digit 0-9. n repeats 5 times and x 4 times... I tried with something like below: ls -l testfile_/\{5\}/* to start with but its not working. Please could anyone help? Thanks D (1 Reply)
Discussion started by: deepakgang
1 Replies

7. Linux

Regular expression to extract "y" from "abc/x.y.z" .... i need regular expression

Regular expression to extract "y" from "abc/x.y.z" (2 Replies)
Discussion started by: rag84dec
2 Replies

8. UNIX for Dummies Questions & Answers

Regular expression

Hello, I have a string of the form " &x.y.z" I would like to grep all the lines when "in" can be found in either x or y. How to write the corresponding regular expression ? I have tried the following but it does not work: grep -i " *&.*(in)*.*.*(in)*.*" Any ideas ? Thank you Max (1 Reply)
Discussion started by: maxvirrozeito
1 Replies

9. UNIX for Dummies Questions & Answers

regular expression..help!!

need regular expression matches: abc11_efg11_123.xml abc11_123.xml Thank you Andy (1 Reply)
Discussion started by: andy2000
1 Replies

10. Shell Programming and Scripting

Regular Expression + Aritmetical Expression

Is it possible to combine a regular expression with a aritmetical expression? For example, taking a 8-numbers caracter sequece and casting each output of a grep, comparing to a constant. THX! (2 Replies)
Discussion started by: Z0mby
2 Replies
Login or Register to Ask a Question