Define File in C
A "file" is a logical description of information kept on an indefinite storage media, like a hard drive, a solid-state drive, or other storage device, in C programming. Programs can save and retrieve data across different programming runs thanks to files' capability for reading and writing text from internal to external storage.
In C programming, there are two primary types of files:
1.Text Files: Text files use ASCII or Roman encoding to represent letters and lines to maintain data in a human-readable format. Text files comprise code sources, configuration, and simple text documents as examples.
2. Binary Files: Binary files, which are frequently utilized to store complicated structures of information or non-textual data like pictures, video, audio, or built programs, maintain information in a format that is not human-readable.
The <stdio.h> header declares the standard functions of libraries and types that C offers to interact with files. Many frequently used file operations functions are as follows:
- fopen(): Allows you to read or write into a file.
- fclose(): shuts down an open file.
- fprintf(): The function writes formatted data in text mode to a file.
- fscanf(): Reads text-mode structured data from a file.
- fwrite(): writes binary data in binary mode to a file.
- fread(): Reads data that is binary in binary mode from a file.
- feof(): determines whether a file has reached its end.
- fseek(): repositions the file reference to a certain spot inside the file.
- ftell (): returns the file pointer's current location.
- rewind (): brings the file reference to the file's start.
Here is an easy representation of how to open a text document for editing and then close it:
#include <stdio.h>
int main() {
FILE *file = fopen("cse.txt", "w"); // Open for writing
if (file == NULL) {
printf("Error in opening the file!\n");
return 1;
}
fprintf(file, "Hello, People!\n"); // Write data to the file
fclose(file); // Close the file
return 0;
}
Output:
![Define File in C](https://static.tutorialandexample.com/c/define-file-in-c1.png)
Standard Streams:
When a program starts up, C offers three basic streams that are already open:
1. stdin: stream containing common input. This is utilized for input redirection or reading user-provided data.
2. stdout: stream of output standards. For writing standard output data, this method is used.
3. stderr: stream of standard errors. Error messages are written using this.
Using routines like scanf(), printf(), along with fprintf(), you can make use of these streams just like conventional files.
Flushing Buffers:
Data is commonly buffered to improve performance before being written to a file. When the memory buffer is filled or independently flushed, the data is gathered in a storage device and then transferred to the file. To immediately write data to the file and flush the buffer, use the fflush() function.
FILE *file = fopen("cse.txt", "w");
fprintf(file, "Hello , ");
fflush(file); // Flush the buffer
fprintf(file, "people!");
fclose(file);
Output:
![Define File in C](https://static.tutorialandexample.com/c/define-file-in-c2.png)
File I/O Errors:
Numerous factors, including insufficient permissions, disc space limitations, and file not found, could cause file operations to fail. To ensure that your software is strong, handling these errors is crucial. The latest file-related error that happened can be printed with the help of the perror() function.
FILE *file = fopen("cse.txt", "r");
if (file == NULL) {
perror("Error in opening the file");
return 1;
}
Output:
![Define File in C](https://static.tutorialandexample.com/c/define-file-in-c3.png)
Temporary Files:
Temporary files can be developed with the tmpfile() method, and temporary file names can be generated utilizing the tmpnam() and tmpnam_s() routines. You often use temporary files when you need to create and utilize a file for a brief period but want to avoid clogging the filesystem with persistent files.
File Management:
The C common library includes methods to handle files, such as rearranging files with the rename() function, removing files with the remove() function, and determining whether a file is present with the access() function.
Binary Data Serialization:
When interacting with binary files, you frequently have to deal with data serialization and deserialization. Complex data structures must be converted into a binary form that can be put into a file and then read back into when reading. For this, methods like bit modification and structural packing are frequently employed.
File Locking:
By prohibiting other programs from simultaneously editing the same file, file-locking innovations let you restrict who has access to a given file. In multi-process situations, this can be critical for preventing data corruption.
Directory Manipulation:
Additionally, C has functions for interacting with directories, such as mkdir() for creating directories and opendir() and readdir() for accessing their contents.
Remember that while working with file processes in C, effectively handling errors, paying attention to platform-specific behavior, and knowing the type of information you are dealing with are all crucial.