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#include <termio.h>
#include <stdio.h>
main(argc, argv)
int argc;
char **argv;
{
struct termio tio, tin;
if (argc < 2) {
fprintf(stderr, "Usage: %s file [file ...]\n", *argv);
exit(1);
}
/*
* In real life we'd check the return value of
* this, since if the input is redirected from a
* file it will fail. We are assuming the
* terminal is always connected to the standard
* input.
*/
ioctl(0, TCGETA, &tio);
tin = tio;
tin.c_lflag &= ~ECHO; /* turn off ECHO */
tin.c_lflag &= ~ICANON; /* turn off ICANON */
/*
* Emulate CBREAK mode.
*/
tin.c_cc[VMIN] = 1;
tin.c_cc[VTIME] = 0;
/*
* Set the new modes. Again we ignore return
* values.
*/
ioctl(0, TCSETA, &tin);
while (--argc)
more(*++argv);
/*
* Reset the old tty modes.
*/
ioctl(0, TCSETA, &tio);
exit(0);
}
/*
* more--display the file.
*/
more(file)
char *file;
{
FILE *fp;
int line;
char linebuf[1024];
if ((fp = fopen(file, "r")) == NULL) {
perror(file);
return;
}
/*
* Print 22 lines at a time.
*/
for (;;) {
line = 1;
while (line < 22) {
/*
* If end-of-file, let them hit a key one
* more time and then go back.
*/
if (fgets(linebuf, sizeof(linebuf), fp) == NULL) {
fclose(fp);
prompt();
return;
}
fwrite(linebuf, 1, strlen(linebuf), stdout);
line++;
}
prompt();
}
}
/*
* prompt--prompt for a character.
*/
prompt()
{
char answer;
printf("Type any character for next page: ");
answer = getchar();
putchar('\n');
}
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