I’m working on a program that needs to store some information and I’ve decided to use a simple file for it. When the program starts it executes the following code, which should result in a file opened in append mode if it exists, or created if it doesn’t (The first time the program loads it …
Tag: file
How to get the lines in one file which contain a string(with repetition) in another file?
File 1: File 2: My desired output: I am trying to implement this using bash or Python. In python I tried: In bash I tried: But this does not consider repetitions. It will give the output Any ideas? Answer Here’s one way you could do it using awk: Read the key-value pairs from the second file into the ar…
How to get all lines from one file which contain a string in another file?
File 1: File 2: My desired output: I am trying to implement this using bash or Python. In python I tried: In bash I was thinking of using grep but grep will give the output that matches the entire line but this is not the case here. Any ideas? Answer This is what works finally.
What is a better way to read each line in a file in linux?
Hi all, I want to read each line in a file and then make a whole url to do some thing. The above scripts worked, but what is a better way to read file line by line? Thanks. Answer This is a nice example of the useless use of cat, simply use IO redirection: The use of -r in read
C: strtok and newlines in Windows vs Linux
I’m working on a C school assignment that is intended to be done on Windows, however, I’m programming it on OS X. While the other students working on Windows don’t have problems reading a file, I do. The code provided by the tutors splits the contents of a file on n using this code: However,…
I read more than I write in file
I have a file, partitioned in fixed sized blocks. I am copying a test_file.txt into the 3rd block of the file. I read and copied 18 bytes. Then I am trying to copy from the file that very same .txt file I just imported to a newly created .txt, but I am writing 256 bytes to the new file. Moreover,
How do I do a one way diff in Linux?
How do I do a one way diff in Linux? Normal behavior of diff: Normally, diff will tell you all the differences between a two files. For example, it will tell you anything that is in file A that is not in file B, and will also tell you everything that is in file B, but not in file A.
Invalid conversion from ‘FILE* {aka _IO_FILE*}’ to ‘int’
When trying to compile this little example… …I get a compiler error regarding the call to lseek(). The output is: For the record: I have also tried using both lseek(*foo, 5, SEEK_CUR); and lseek(&foo, 5, SEEK_CUR);, but that only makes things worse. (I really didn’t expect that to solve …
Alternative to writing many files. MongoDB?
I have a Perl script that produces ~10000 files in the 1kB – 10kB size area, which is not optimal for performance, so I though about using MongoDB instead of writing the many files. I need to run the script on my laptops Linux and OSX. Question Would MongoDB be overkill? Or are there something more suit…
Unable to configure folder permissions in Ubuntu
I found many related questions and tried to solve the issue but I was not successful. Actually I created an user named “amit” and assigned the group “www-data”. I gave permission to the folder using this method Change folder and file permission recursively: To change all the directorie…