In C programming, the fputs function is employed to insert a line of characters into a file. This function sends a string to a stream by writing all characters from the string until the null character marks the end. It is a useful tool for saving text in files or directing output to a particular stream.
Syntax:
It has the following syntax:
int fputs(const char *s, FILE *stream)
In this format,
- S denotes the string that needs to be written.
- *stream is utilized to symbolize the file pointer.
Simple C fputs Function Example
Let's consider an illustration to showcase the implementation of the fputs function in the C programming language.
Example
#include <stdio.h>
int main() { // main function
FILE *fp;
fp = fopen("myfile2.txt", "w");
if (fp == NULL) {
printf("Error opening file!\n");
return 1;
}
fputs("Hello! This is a C Programming Language", fp);
fclose(fp);
return 0;
}
Output:
Hello! This is a C Programming Language
Explanation:
In this specific instance, we initiate the opening of a file named myfile2.txt in write mode through the invocation of the fopen function. Should the file opening process encounter an issue, an error message is displayed, and the program halts its execution. Subsequently, the fputs function is employed to inscribe a string into the file, followed by the utilization of the fclose function to conclude the file operation, guaranteeing the accurate preservation of the data.
Features of the fputs Functions in C
There are several features of the fputs Function in the C programming language. Some of them are as follows:
- The fputs function in C is commonly used to write a line of characters into a file.
- This function is commonly utilized to write a complete null-terminated string to the specified file or stream.
- It can be utilized in the stdout and stderr. It can also be used to open any file using the fopen function.
- It can help to find errors, such as write issues or invalid file pointers.
- It is very helpful to write logs, messages, and text files.
Reading File: fgets Function
In C programming, the fgets function is frequently employed for retrieving a line or a specific character count from a file. This function allows for reading characters until encountering a newline (\n), reaching the end of the file, or reaching the designated limit. Using fgets also allows for saving the outcome in a character array while ensuring a null terminator (\0) is always included, enhancing the safety and reliability of string manipulation.
Syntax:
It has the following syntax:
char* fgets(char *s, int n, FILE *stream)
- s: It represents the character array where the read string will be stored.
- n: It is used to represent the maximum number of characters to read.
- *stream: It is used to represent the file pointer.
Simple C fgets Function Example
In this example, we will showcase the fgets function within the C programming language.
Example
#include <stdio.h>
int main() { // main function
FILE *fp;
char text[300];
fp = fopen("myfile2.txt", "r");
if (fp == NULL) {
printf("Error opening file!\n");
return 1;
}
if (fgets(text, sizeof(text), fp) != NULL) {
printf("%s", text);
}
fclose(fp);
return 0;
}
Output:
Hello! This is a C Programming Language
Explanation:
In this provided instance, we initiated the opening of the file named myfile2.txt in read mode and verified its successful opening status. Subsequently, we employed the fgets function to extract a line of text from the file and store it in a character buffer. If the reading process is executed without errors, the obtained line is exhibited on the screen. Finally, the file is closed to free up system resources.
Features of the fgets Functions in C
There are several features of the fgets Function in the C programming language. Some of them are as follows:
- The fgets function in C is commonly used to read a line or a fixed number of characters from a file.
- This function can stop reading when we encounter a newline, hit EOF (end-of-file), reach the specified length, and many others.
- It helps to ensure that the string is completely terminated with the '\0'.
- It helps to store spaces, punctuation, tabs intact, and many others.
- It can be used to read configuration files, text processing, file parsing, and many more.
Conclusion
In summary, the fputs and fgets functions in C offer a secure, dependable, and effective approach for managing file operations based on strings. With fputs, users can easily write entire strings to a file or output stream without any additional formatting. Conversely, fgets ensures a secure and controlled reading of text, preventing buffer overflows and preserving spaces and special characters. Together, these functions form a powerful duo for text data manipulation, making them ideal for tasks like file handling, logging, and user input management in contemporary C development.
C fputs and fgets function FAQs
No, the fgets function in C does not automatically append a newline character to the input it reads.
No, the fgets function does not automatically append a newline character. It reads characters from the input stream and includes a newline character, '\n', in the copied string if it encounters one before reaching the character limit. After that, it adds a null terminator, '\0', to mark the end of the string.
No, the fputs function in C does not write the null character.
No, the 'fputs' function does not include the null character in the output. Instead, it ceases writing characters upon encountering the null character, represented as '\0' within the input string. The null character is not included in what is written to the output stream.
The main difference between fputs and fgets compared to puts and gets in C is that fputs and fgets are used for handling files, while puts and gets are used for standard input and output. While fputs is specifically designed to write a string to a file, fgets is used to read a string from a file. In contrast, puts is used to display a string on the standard output, and gets is used to read a string from the standard input.
Let us compare the following points:
a. Fputs vs. puts
The fputs function necessitates a file pointer parameter enabling output to any stream, while the puts function solely writes to the standard output, namely 'stdout'. Unlike puts, fputs writes the exact string specified without adding a newline character ('\n') automatically at the end, thus giving more control over the output format.
b. Fgets vs gets
The fgets function is widely regarded as a more secure alternative to the gets function due to its inclusion of a size parameter 'n'. This parameter restricts the number of characters read, effectively preventing buffer overflows. In contrast, the gets function lacks this safeguard against buffer overflow and is either deprecated or deemed unsafe for use.
4) Is it possible to utilize the fgets and fputs functions for handling standard input and output (console I/O) in the C programming language?
Yes, the 'fgets' and 'fputs' functions can be applied for handling standard input/output (console I/O). The FILE *stream parameter can represent a file pointer, which is acquired through the 'fopen' function or one of the pre-defined standard streams. The 'stdin' stream is employed with the 'fgets' function to receive input from the keyboard, while the 'stdout' stream is utilized with the 'fputs' function to output to the console.
5) Do more effective string input/output functions exist in the C programming language?
The fgets and fputs functions are commonly suggested as secure options for handling text I/O in a line-oriented manner. These functions leverage the internal buffering capabilities of the standard I/O library, known as 'stdio', to reduce the frequency of slower system calls to the operating system. In most cases of basic string I/O operations, there is usually no requirement to seek out more efficient alternatives unless there are specific, performance-driven demands in place.