Programming :: Read A Line From A Txt File In A Script?
Dec 9, 2010
have been playing around with a script for a few hours and now I need to be able to output the lines in a text file one by one to be used later in the script.What it gonna do is to read a log file and grep the usernames, then write them to a file, and then run one script for each user, to search for more information about them in the log.But I don't know how to output a single line from a file, and google does not return any solution.
I have two txt files containing x and y coordinates: xcoord.txt & ycoord.txt. I need to open them; read them line by line to get each coordinate; then each time I need to update Xs and Ys parameters inside another file called "dc.in" with the grabbed values.
Finally each time I need to run two exe files ( dc_2002 and st_vac) and produce corresponding output for each Xs and Ys ( dc.in is an input file for this exe files)
I have written the following code but it does not work:
bash 3.1.17(2) I'm trying do write a shell script which must operate on each line of an ASCII text file. So, all the code must be inside a loop, and inside the loop, the first thing should be to read the next line from the file. I have the bash read command. But it reads from stdin. Any way to make read from a file?
I need a qtimer to trigger reading of a file line by line, I have the code sort of running with the timer trigger but qtimer will just read the first line over and over as it is now.
when I ran both ldapsearch commands invidually, they work fine. But when I ran script, I got first file correctly but not the second one. It looks like its not reading the first file correctly and not setting the variable ($userdn) value correctly in the second ldapseach command. I want read first file first line and run the second ldapsearch and continues, then read the second line..and so on.
i am trying to read in a file 1 line at a time and for some reason it stops printing out at about line 62,000.
i am doing this: Code: while(fgets(c0, 1085, fstream0) != NULL)
but after about 62,0000 lines it stops printing. no seg-fault, no core dump. it just stops printing to the terminal then returns me to the command line after a couple of minutes. as a hack i am doing split -l 50000 on the input and calling my program 5 times.is there some limitation on fgets that i am not understanding ?
I'm writing a program which now accepts user input:
Code: echo "Enter a date in the format YYYY MM DD hh mm ss."
read gregyr gregmo gregdy greghr gregmn gregsc This lets the user input a date and time, such as 2011 06 21 15 12 45, and have each number assigned to their corresponding variable. Later in the program, these variables are put into an equation, and then the terminal spits out the answer. Now I have to have the program read all of the lines from a text file, which is in this format, assign the variables.
I ran into it while google Segmentation Fault. I'm writing a simple C program that reads a file that counts each line and numbers it then writes to a file called sdout. I copyed my program mostly from the text book but im still having problems. Heres my code:
instead of importing a file I would like to use the variable $x I tried using pipes, but with no luck. My goal is to read one line at a time, but not have to export my data to another file, I would like to keep it all within one script.
I just learn perl script.May i know how to simplify the code below especially in the red color part? i saw some examples in internet, they use "next" command.
I want to access a file, and check the length of every line.After, i want to check and replace all lines with length over 10 characters, with a message.Does anyone have a clue on that?
read a files's specific line but return as argument only part of it ie
...
value # this is mass
value2 # this is force
so, how can I get / use the $value and $value2 as arguments for some other file and skip the rest of the line(s) ? of course, the values are different everytime, but the comment always the same, as well as the position of the lines in the file
I am trying to read the names of hosts from a file and do a ssh to see if processes are all running or not.
Here is the outer loop that is causing problem:
hosts.lst is a text file that has the host names in each line.
The problem is that the loop just breaks after the first run. Somehow while read line becomes invalid when the body of the loop does the ssh and returns.
I have a project due for my Intro to C++ class and we are suppose to generate a file listing that will take an input of a C++ source code with .cpp extension and make a copy of it with a .lst extention that will have a line number preceding each and every line.
I wish to add information to one of my files based on matching IDs,
Here is an example
(the id is the 3 colunm)
(the ID is the 2 colunm)
And the output i wish to be
OUTPUT:
So as you can see the ones that do not match are still present, and the ones that do match just have the extra information from file2.txt added to them.
I thought about using join but that only seems to join the ones that match displays thoes only. i would like all the information in the output file.
Was wondering if any perl guru's could help me with a quick log file adjustment. I have a text file that looks like so (tabs and newlines are revealed so you can see what separates the data):
There are maybe 100 lines of text in this file at any given time. I need to delete all duplicate lines only looking at the first bit of text prior to the first tab. It doesn't matter which one gets deleted as long as there are no two lines that begin with that same text at the beginning before the first tab. So in this example, either the fist line "1234" or the last line "1234" would need to be deleted. I already have code in my script that opens the files - I just need the code to read the text into an array and the part that would find matches based on the above criteria, and make the deletions.
If it would be easier, I can even do a system call and use SED (v4.1.5) and/or AWK (3.1.5) instead.
In C, I want to make a program that will take a file and replace it with a file that's nearly the same but with some minor changes. Also, I would like to point out that I'm still fairly much a beginner with C. As for an example of the file, I want to take something like this:
Code:
Random Crap More Random Crap Even More Something That Changes XXXXX
[code]....
I figured the best way to go about doing this was to open the file and a blank file, read the original bit by bit and when it gets to the point that needs to be changed exchange the part that needs to be changed with what it should be changed to, delete the original file, and rename the new one to the correct name. So the first problem I've run into (and I'll probably have more) is that when I'm trying to read stuff from the original file, my program doesn't seem to be finding the original. I'm sure much of my problems will be just from not knowing how to use the C functions so bear with me. Right now I have the following:
Died Here: No such file or directory Segmentation fault
Right now the length of 50 was just a random test length. Pretty much I was just trying to get it to read anything from the file. In the end I'm going to want it to read the entire file bit by bit, but at the moment I can't seem to get it to read anything.
Trying to create a small script that will read user's input, test if user entered some input and if not display some message or display a text using user's input.
The script is the following but i get an error saying "[: 6: =: argument expected"
I need to edit a line in a file in gedit, but its read only. I need to change
; default-sample-rate = 44100 to default-sample-rate=44800.
Would anyone know if there is an option to make a read only file editable? Judging by the responses to the thread I followed to enable my soundcard, it is possible, and perhaps there is some setting etc that needs changing
I simply want to read a file "data.txt" line by line Then char by char and add them into a result var. The file is supossed to always contain numeric values
I need to run a command in a shell script to insert a line in a file, after it finds certain line. To add the line 'user = mysql' after the line [mysqld] in file /etc/my.cnf
basically i have to create a simple program with will continually read input from the user until they enter a blank linei know how to read in certain input but not sure how to get it continually in a loop
I am splitting a file based on the values read from an input file. The below one is the script.
1)How do I add the header which is present in the original file to the new split files created?(For eg. pharmacyf conatins header as table column names. The new files created (ODS.POS.$pharmacyid.$tablename.$CURRENT_DATE.dat) are without the header).
2) Also the script is creating 0 byte files for the pharmacyids which are not available in the intial file? Can this be avoided?
for pharmacyf in * do tablename=`echo $pharmacyf |cut -f4 -d'.' ` while read pharmacyid do grep -w $pharmacyid $pharmacyf >> $OUT/ODS.POS.$pharmacyid.$tablename.$CURRENT_DATE.dat done< inputfile done
