Programming :: Reading Specific Lines From A File?
Sep 10, 2009
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++.
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.
I'm trying to come up with ideas for a simple way to strip a specific "entry" from a text file.I know tools like sed and perl can remove specific lines from a file but I haven't been able to come up with an elegant way to do my group of lines.In my file, the first "Location" line and the "SVNPath" line should be unique every time... but are they enough to strip out the whole set of the group plus the trailing one line of white space separating each group? Add to this, my file will grow as new entries are added (always appended to the end) but new entries will have the same formatting.
I'm trying to extract specific lines from a flat file. I need lines that fall within a range of coordinates. The -F can be either ! or = If the line is in this set range I need all of the data on that line. ranges lat 36 to 39 and longitude -74 to -84
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
I have text file with say 1000 lines.And I want to display lines numbered 100, 203 and 297 using a script/ command.How can I do this ?I can print a particular line using:sed -n '100p' file1 (where file1 is input file).
I would like to parse an input file in which there are two columns per each row. We want to see how many lines are duplicated where we define duplicate to be having the same second field and different first field. For instance if the input file looks like the following:
A function by name abc is called in many files. I want to copy all the lines with the function call to an output file.A simple grep on function name doesn't help me as the function call is spanning across multiple lines as follows:
abc(parameter1, parameter2, parameter3);
So I want to copy all the three lines (till semicolon) to the output file.The problem is because there are more than 200 calls for the same function and I cannot do it manually
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 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).
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 {
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.
I need to read a binary file using my C++ application. That binary file may contain arbitary characters and it also contains 0 at some places. I need to read the file without considering null terminating character. (i.e. considering 0 as a normal byte and not as the end of the string)Can some one suggest me a method to read the buffer while ignoring the null terminated character.
I would like to read unix file permissions into a bash array for processing but tbh I have no idea how to do this. Then I will check for each individual access right l, d, x etc.
