/* * Concatenate files. */ #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> char stdbuf[BUFSIZ]; main(argc, argv) char **argv; { int fflg = 0; register FILE *fi; register c; int dev, ino = -1; struct stat statb; setbuf(stdout, stdbuf); for( ; argc>1 && argv[1][0]=='-'; argc--,argv++) { switch(argv[1][1]) { case 0: break; case 'u': setbuf(stdout, (char *)NULL); continue; } break; } fstat(fileno(stdout), &statb); statb.st_mode &= S_IFMT; if (statb.st_mode!=S_IFCHR && statb.st_mode!=S_IFBLK) { dev = statb.st_dev; ino = statb.st_ino; } if (argc < 2) { argc = 2; fflg++; } while (--argc > 0) { if (fflg || (*++argv)[0]=='-' && (*argv)[1]=='\0') fi = stdin; else { if ((fi = fopen(*argv, "r")) == NULL) { fprintf(stderr, "cat: can't open %s\n", *argv); continue; } } fstat(fileno(fi), &statb); if (statb.st_dev==dev && statb.st_ino==ino) { fprintf(stderr, "cat: input %s is output\n", fflg?"-": *argv); fclose(fi); continue; } while ((c = getc(fi)) != EOF) putchar(c); if (fi!=stdin) fclose(fi); } return(0); }