Recognizing EOF vs newline in getline in C

user_14579957 0
Viewed 931

is there any way how to recognize if getline was ended because of newline or because of EOF?

So, I would like to distinguish:

1. alfa \n beta \n gama \n EOF

2. alfa \n beta \n gama EOF

In the second case I don't want to read gama as a new string and I want to say, that the reading of last string was not successful. I am using while cycle to read the lines.

I can't edit incoming data.

There is probably possibility to solve this by using getchar. However it makes reading lines more complicated :-/

Thank you so much

getline eof newline c
3 Answers

Like fgets(), getline() includes the trailing newline in the string. So just check the last character after a successful call to see if it's a '\n'. If it's something else, you have the last line of a file without a trailing newline.

user_99521960

is there any way how to recognize if getline was ended because of newline or because of EOF?

If the line input stopped due to end-of-file, feof() returns true.

ssize_t nread = getline(&line, &len, stream);
if (feof(stream)) {
  puts("Input ended due to end-of-file");
}
if (nread > 0 && line[nread-1] == '\n') {
  puts("Input ended due to end-of-line");
}

It is possible for both to be false: input error or allocation failure.

Concerning fgets(), additional issues occur when the buffer is full or a null character was read.

user_24103590

Thank you for your tips.

Finally I used easier way how to do it.

characters = getline(&line, &len, stream);

if (characters==-1) {puts("Input ended by EOF after \n");}

if (feof(stdin)) {puts("Input ended by just EOF");}

user_145799570
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