You must supply at least as many characters of space in the string, or your program might crash, but at least the fgets function protects against overflowing the string and creating a security hazard.
If there is no error, fgets returns the string read as a return value else for example if the stream is already at end of file, it returns a null pointer. Unfortunately, like the gets function, fgets is deprecated, in this case because when fgets cannot tell whether a null character is included in the string it reads. If a null character is read by fgets, it will be stored in the string along with the rest of the characters read.
Since a null character terminates a string in C, C will end your string prematurely, right before the first null character. Only use fgets if you are certain the data read cannot contain a null; otherwise, use getline. Using getline function in C: Preferred Method : The getline function is the preferred method for reading lines of text.
The other functions like gets, fgets, and scanf, are unreliable for reasons already seen above and must be avoided. The getline function reads an entire line from a stream, up to and including the next newline character. The first is a pointer to a block allocated with malloc or calloc which allocates memory for the program when run.
The third parameter is simply the stream from where to read the line. The getline function automatically will enlarge the block of memory as needed, via realloc function, so there is never a shortage of space one reason why getline is safe.
We will understand better in the below mentioned example. It will also tell us the new size of the block by the value returned in the second parameter. If an error occurs, such as end of file etc. Although the second parameter is of type pointer to string , you cannot treat it as an ordinary string, since it may contain null characters before the final null character marking the end of the line.
The return value enables you to distinguish null characters that getline read as part of the line, by specifying the size of the line.
Here is an example of how to use getline to read a line of text from the standard input. How have you been? You entered the following string: Hello! Current size for string block: 27 Here we have typed more than 10 characters. However, getline still safely handled the input and read the data entirely as it dynamically reallocates space to accomodate the string.
Using getdelim function: Preferred Method : The getdelim function is a more general form. In fact, getline simply calls getdelim and specifies that the delimiter character is a newline. The syntax for getdelim is nearly the same as that of getline, except that the third parameter is the delimiter character, and the fourth parameter is the stream from which to read.
In order to read a string, we have to use this function repeatedly until a terminating character is encountered. The characters scanned one after the other have to be stored simultaneously into the character array. Entered string is: Where have you been? Hence condition is checked against it. This function prints a text string to the terminal i. It is one of the preferred modes to output a string. It enables us to print formatted output; thus giving us flexibility.
Using puts function: Preferred : Using puts , string can be displayed as follows: It just takes its parameter as the string to be printed.
The most convenient function for printing a simple message on standard output is puts. It is even simpler than printf, since you do not need to include a newline character — puts does that for you. How can I read separate strings from text file?
How can I get first letter not number from seperate strings? By the way, I've wrote code, that takes only first char of text file and changes numbers into it, whenever it's number or not, but I dont know how to add code here Write a function that accepts a string and converts it as you described. Do this first. And test it well because it is the fundamental part of the program. Now you want to read a text file from main and simply display each word on screen in it's own line.
This is to help you understand how to read words from a file. I would use fscanf for this. Make sure you can read the entire text file and it doesn't crash. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Get first char of every string from text file in C Ask Question. Asked 7 years, 3 months ago. Active 7 years, 3 months ago. It is important to maintain the original pointer returned by malloc so that you can free it later.
If we disregard the file size, we can achieve this still with the following:. There are various system calls that will give you the size of a file; a common one is stat.
I think the most significant problem is that you're incrementing code as you read stuff in, and then returning the final value of code , i. You probably want to make a copy of code before the loop, and return that instead. Also, C strings need to be null-terminated. Note: You could just use fgets to get the entire line in one hit. Like the other posters have pointed out, you need to ensure that the file size does not exceed characters.
Also, remember to free the memory when you're done using it. The second problem is more subtle - fgetc returns an int so that the EOF value can be distinguished from any possible char value. Stack Overflow for Teams — Collaborate and share knowledge with a private group.
Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Reading a file character by character in C Ask Question. Asked 10 years, 11 months ago. Active 1 year, 7 months ago. Viewed k times. Right now here is what I have. Improve this question. NAND 8 8 silver badges 22 22 bronze badges. Devan Buggay Devan Buggay 2, 4 4 gold badges 24 24 silver badges 34 34 bronze badges. Add a comment. Active Oldest Votes.
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