Learn to Program with C_ Learn to Program using the Popular C Programming Language ( PDFDrive )

Chapter 5 ■ Programs with Repetition Logic
• The numbers in the file could be supplied in “free format”—any amount
could be put on a line. For example, the sample data could have been typed
on one line as above or as follows:
24 13
55 32
19 0
or like this:
24 13
55
32 19
0
or like this:
24
13
55
32
19
0
• As an exercise, add statements to the program so that it also prints the
largest and smallest numbers in the file.
■■File cannot be found when you try to run this program, it may not run properly because it cannot find the
file input.txt. This may be because the compiler is looking for the file in the wrong place. Some compilers
expect to find the file in the same folder/directory as the program file. Others expect to find it in the same
folder/directory as the compiler. Try placing input.txt in each of these folders, in turn, and run the program.
If this does not work, then you will need to specify the complete path to the file in the fopen statement. For
example, if the file is in the folder data that is in the folder CS10E, which is on the C: drive, you will need to use
the following statement:
FILE * in = fopen("C:\\CS10E\\data\\input.txt", "r");
5.9 Send Output to a File
So far, our programs have read data from the standard input (the keyboard) and sent output to the
standard output (the screen). We have just seen how to read data from a file. We now show you
how you can send output to a file.
This is important because when we send output to the screen, it is lost when we exit the
program or when we switch off the computer. If we need to save our output, we must write it to a
file. Then the output is available as long as we wish to keep the file.
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