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

Chapter 8 ■ Arrays
Suppose we have the following declarations in main:
FILE * input = fopen("quizdata.txt", "r");
char country[50];
and the file quizdata.txt contains strings delimited as described above. We would be able to
read the next string from the file and store it in country with this:
getString(input, country);
It is up to us to ensure that country is big enough to hold the next string. If not, the program
may crash or nonsense results will occur.
Here is getString:
void getString(FILE * in, char str[]) {
//stores, in str, the next string within delimiters
// the first non-whitespace character is the delimiter
// the string is read from the file 'in'
char ch, delim;
int n = 0;
str[0] = '\0';
// read over white space
while (isspace(ch = getc(in))) ; //empty while body
if (ch == EOF) return;
delim = ch;
while (((ch = getc(in)) != delim) && (ch != EOF))
str[n++] = ch;
str[n] = '\0';
} // end getString
Comments on getString
• The predefined function isspace returns 1 (true) if its char argument is a
space, tab, or newline character and 0 (false), otherwise.
• If getString encounters end-of-file before finding a non-whitespace
character (the delimiter), the empty string is returned in str. Otherwise, it
builds the string by reading one character at a time; the string is terminated
by the next occurrence of the delimiter, or end-of-file, whichever comes first.
• We can read a string from the standard input (the keyboard) by calling
getString with stdin as the first argument.
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