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#include<stdio.h>
#define MAXLENGTH 1000
// Prototypes
int get_line(char line[], int maxlength);
void line_copy(char to[], char from[]);
void reverse_copy(char to[], char from[], int length);
/*
* MAIN
* Reverse all lines on STDIN.
*/
int main() {
int len; // current line length
char line[MAXLENGTH]; // current input line
char reversed_line[MAXLENGTH]; // current reversed line
while ((len = get_line(line, MAXLENGTH)) > 0) {
reverse_copy(reversed_line, line, len);
printf("%s\n", reversed_line);
}
return 0;
}
/*
* GET_LINE
* Read STDIN into LINE up to MAXLENGTH.
* Returns the length of LINE.
*/
int get_line(char line[], int maxlength) {
int c, i;
for (i = 0; i < maxlength - 1 && (c = getchar()) != EOF && c != '\n'; ++i)
line[i] = c;
if (c == '\n') {
line[i] = c;
++i;
}
line[i] = '\0';
return i;
}
/*
* LINE_COPY
* Copy FROM into TO; assume TO is big enough.
*/
void line_copy(char to[], char from[]) {
int i;
i = 0;
while ((to[i] = from[i]) != '\0')
++i;
}
/*
* REVERSE_COPY
* Copy FROM into TO (of length LENGTH) in reverse order; assume TO is big
* enough.
*/
void reverse_copy(char to[], char from[], int length) {
int i;
for (i = 0; i < length; ++i) {
to[length - 1 - i] = from[i];
}
to[length] = '\0';
}
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