#include #include "ourhdr.h" #define PAGER "${PAGER:-more}" /* environment variable, or default */ int main(int argc, char *argv[]) { char line[MAXLINE]; FILE *fpin, *fpout; if (argc != 2) err_quit("usage: a.out "); if ( (fpin = fopen(argv[1], "r")) == NULL) err_sys("can't open %s", argv[1]); if ( (fpout = popen(PAGER, "w")) == NULL) err_sys("popen error"); /* copy argv[1] to pager */ while (fgets(line, MAXLINE, fpin) != NULL) { if (fputs(line, fpout) == EOF) err_sys("fputs error to pipe"); } if (ferror(fpin)) err_sys("fgets error"); if (pclose(fpout) == -1) err_sys("pclose error"); exit(0); }