Programming :: Reading Lines Within A File (Perl)?
Mar 16, 2011
I am trying to read certain lines within a file and give the output of the certain lines that dont equal my value, I think showing you would be easier. There is multiples of these inside one file...
Code:
LV Name /dev/vg00/lvol1
LV Status available/syncd
LV Size (Mbytes) 300lable/syncd
[code]....
I want to read everything in the file, if the status is not available then it should display the name (directly above status). If they are all availbale then do nothing. I think I know how to do it which includes putting the info in string form and placing in hash but it is proving to be out of my skill range.
To save on the writing of WAY to many files with very little in them, I want to put it all in one file and read a specific few lines. There will be six variables to be read at a time. Format is as such:
//Set 1 string name 5 12
[code]....
From name to 5th number is a set. The name will be of different lengths for each set. This will be a big file of probably 40+ sets. My problem lies in reading one and only one set be it set 5 or set 34. It needs to be done in C++.
There is the Archive::Zip I think I can use with Perl 5.10 but I don't know how. I don't want to read or write any files, just zip something in memory, with best compression, like
$text = "this is a test"; $zippedtext = &Zip($text); sub Zip {
Order of these lines are random... So I cannot delete line #19, for example... And you can see that top four lines I want to delete are pairs. So there might be some clever way to detect the lines, if a line has both "1.9" and "1.11", then delete the line... I am new to perl language. The following is the code I have now... I think I just need to write some code inside the while loop checking if I want to delete the line $dotline before I write to a NEW file.
Each line of the file I am sorting is in the following format:
<url> <month> <day>
For example:
[URL]
I wrote the following to sort:
Code:
#!/usr/bin/perl $in = shift; chomp($in);
[code]....
The script worked fine for my small testing files, but failed in my input file. The input file is 18MB and containing more than 300,000 lines. The output will contains some lines like that:
I am trying to create a script that reads a list of url's from a text file and then executes the same script for each line. This is what I am looking for:
elinks -dump $(url's in file, one by one) | grep "reply" > jobs.txt
there is a way to add line spaces when asking for user interaction in a script. For example:
Code:
SPACE Hello what is your name? SPACE SPACE
So this is asking a question but has a space/empty line at the top of the screen and 2 spaces/empty lines below. I've seen it done in a bash script using for each line/space needed
I want to read the user username and password available in a password file. I want the password to be stored in a user home directory and my perl script should read , whenever needed from that file. Am not a Perl programmer and I want to set this for admin related activities. In what syntax I need to write the password file and How to call them using the perl script.
What is the best way to merge lines, in sed, awk or perl, that occur between certain strings? I'm new to sed scripting and I have been working on this for some time now. I have a large file (sample below) that I need to edit.
What I need looks something like this.
I'm working with a very large file so simply merging all the lines then adding a new line character before ">contig" and after "translated" won't work, at least not with sed.
I'm trying to split a text file into various parts. Everything in between "123" and "break" (including linebreaks) goes into the splitted file.
e.g. using this text file:
This should split into 4 files. However I'm only getting 2 files: one for the line "123break" and one for "123 blah break". The two occurrences that contain linebreaks are being ignored. The .* part of my match should capture linebreaks seeing that I'm using the /s modifier shouldn't it? Even when I use the match /(123 break)/gs it still doesn't capture the first occurrence. I'm using Perl v5.12.3 (from ActiveState) on Windows XP. The text file is also in Windows format.
Code listed below.
The above code generates two files Output_1.txt and Output_2.txt which contain "123break" and "123 blah break" respectively. I want it to generate four files.
I am new to perl and am having trouble adding some strings together.
My full code is below:
The problem is $NewCommandB is always split into two lines, where the second line contains the "/atlas2/<blah>/<etc>/..." string. Since I am generating a .sh file to execute a lot of similar commands I need the string to all be on one line. Any idea why I get this behaviour and any suggestion on how to tell perl to make $NewCommandB a one line string?
Btw for completeness finalFileList.txt contains just file names one line after another:
I have a dataset of around 1000 lines. Out of these 1000 lines I need to pick randomly 160 lines of data and write it to a file. The program is needed to eliminate data bias when I run the program through a reanalysis program. I am thinking I need to use the rand or srand term, but I am having difficulty writing this in perl. I have to write it in perl, because the rest of my scripts for this project are in perl, so consistency is important. The data only consists of one column of the data (YYYYMMDDHHHH).
I have written a regular expression (tested in regexpal and regextester alpha something) with which I want to replace something like code...
but it only matches functions which occupy one line only, despite my tests showing multiple line matching in javascript testers online and using the m and s flags (which should make it multi line no?)
I have a binary file, which I need to process using my C++ application. Only thing I know is first chunk of the file is long, second chunk is int, third chunk is char etc... The binary file actually contains something like below. (which is represented in hex base).
D7 07 00 00 00 00 00 00 37 18 00 00 DE 07 ............ so on.....
I need to procees the file in the following way.
* I know the first data segment in my file is long. So it takes 4 bytes. * so I need to read the first four bytes. That is D7 07 00 00. * Then I need to reverse this as 00 00 07 D7. * Finally I need to get the decimal value of above hexa decimal line. ( 00 00 07 D7) * i.e. 00 00 07 D7 (in hex) = 7D7 (in hex- after removing leading 0 s) = 2007 (in decimal)
I have two files of data with different numbers of columns and rows. I want to read this two files in two arrays and then compare for example the second column of first data file with the third column of the other text file and if the difference between of two numbers is less than a threshold then the program print the information in the rows which fulfill this condition in the third text file. I have written below program but the problem is that it does not go through all rows of second file.
declare -a a declare -a b r=` awk '{n++} END {print n}' second.txt ` echo $r awk ' {
[Code]....
Actually I have two data files one of them contains 44406 and the other one has 12066 rows and I want to check whether the difference between the components of two specific columns is less than a threshod but I have simplified it here. I had written this code and then I have realized that this code just goes through the number of rows as the same as the first.txt file and ignores the rest. I could not find the problem yet.
I made a string key-value mapping struct in C, and functions to add and remove entries. I would also like to write a function to read in this file format:
I need to Read a path of a file witch is written in Text file i used this
Code:
FILENAME=$1 while read line do echo $line done < $FILENAME
it worked and showed me the Line witch was written in my file but now my problem is how am gonna use that line as a path i mean for example if am gonna execute a linux command on that file like dpkg -i /path/to/the/file how am gonna export it from The $Line variable and use it after the command.
I have script that I'm working on that updates a username in all the files that are called blah.inc for my framework. since i host a bunch of these web apps i need to do it to all of them. so I need to figure out how to update these files automagically with out me watching it to call vim every time. heres what I have so far
Code:
This finds the files but now i need to figure out how to do s/bob/fred/g on those files.
i have two files with thousands of line, I am trying to combine these two files but i want to insert each line of one file to the another file after certain lines. I am using awk with the following command but it does not work.cat file1 | awk ' { print $0; if (NR%3004==0) {print "file2"}}' > outputfile
I am trying to read a file character wise and trying to write the same character to another file. In this process, I unable to read and write white spaces successfully to the new file. The script reads the white spaces but while writing the white space is lost. The section of the code, is given below. Please advice how can i read and retain the white space while writing to a new file.
Code:
if [ -s f_test.txt ] && [ -f f_test.txt ]; then echo "File Exists !!" while read -n1 char; do
how to program in bash, an i have a problem, i am trying compare values in between 2 values (from another file), so far my solution is to make a nested for loop, but that causes it to compare every value. Here is a visulization of what i want
file.a 2,3,4,5 file.b 3 5
[code]...
i want the values 2, 3, 4, 5 from file.a to be compared inbetween values 3 5, 6 9,1 2, 4 7 from file.b (var1 is the value im comparing, var2 is the less value, var 3 is the greater value)
for i in $var1 do for k in $var2 do
[code]....
my problem with the above code is it compares EVERYINNG, not the values inbetween what i want (which is 3 5, 6 9 etc).
I wanted to read out the absolute file-path (filename) as sorted in a folder (on Linux). The reading the file-paths is ok but I have problems in sorting.
Code:
selectedDirectory = fl_dir_chooser ("Select Imagedirectory:",NULL,0); //This is just a widget to show the folder. DIR *d; dirent *de;
[code]....
The files -105.dcm, -106.dcm, -107.dcm lie in the folder at the bottom and -36.dcm, -37.dcm- at the top. The program compares 1 and 3 of 105 and 37, 1 is lesser than 3, then prints out first, but does not know that 105 is three digits and 37 is two digits.
