Scanning an entire line from a file in C programming

Question

I wrote a program to enter several lines from a file. the problem is that I don’t know the length of the lines, so I can’t use fgets because I need to specify the size of the buffer and not use fscanf because it stops at the space pointer I saw a solution in which he recommended using malloc and realloc for of every character taken as input, but I think there’s an easier way, and then I found someone suggesting using

fscanf(file,"%[^\n]",line);

Does anyone have a better solution or can someone explain how this works? (I did not test it)

I use the GCC compiler if necessary

Answer 1

getline (3). , , .

Answer 2

-, fscanf(file,"%[^\n]",line);

fgets(line, sizeof line, file);. .

, .

• LINE_MAX, - C (AFAIK POSIX, ). , .

• , realloc(). , .. . , .

Answer 3

scanf fscanf

%specifier 

, d - .

[characters] Scanset , .   (-), , .

[^characters]  Negated scanset , .

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fscanf(file,"%[^\n]",line);  

Read any characters before any character appears Negated scansetin this casenewline character

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Like others, you can use getline()or fgets()and see an example

Answer 4

String fscanf(file,"%[^\n]",line);means that it will read anything except \nto line. I think this should work on Linux and Windows. But it cannot work in OS X format, which it uses \rto complete the string.