BSD 4_1c_2 release

[unix-history] / usr / src / usr.bin / touch.c

#ifndef LINT
static  char *sccsid = "@(#)touch.c     4.2 (Berkeley) 82/06/09";
#endif not LINT

/*
*      attempt to set the modify date of a file to the current date.
*      if the file exists, read and write its first character.
*      if the file doesn't exist, create it, unless -c option prevents it.
*      if the file is read-only, -f forces chmod'ing and touch'ing.
*/

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>

int     dontcreate;     /* set if -c option */
int     force;          /* set if -f option */

char *whoami = "touch";

main(argc,argv)
       int     argc;
       char    **argv;
{
       char    *argp;

       dontcreate = 0;
       force = 0;
       for (argv++; **argv == '-'; argv++) {
               for (argp = &(*argv)[1]; *argp; argp++) {
                       switch (*argp) {
                       case 'c':
                               dontcreate = 1;
                               break;
                       case 'f':
                               force = 1;
                               break;
                       default:
                               fprintf(stderr, "%s: bad option -%c\n",
                                       whoami, *argp);
                               exit(1);
                       }
               }
       }
       for (/*void*/; *argv; argv++) {
               touch(*argv);
       }
}

touch(filename)
       char    *filename;
{
       struct stat     statbuffer;

       if (stat(filename,&statbuffer) == -1) {
               if (!dontcreate) {
                       readwrite(filename,0);
               } else {
                       fprintf(stderr, "%s: %s: does not exist\n",
                               whoami, filename);
               }
               return;
       }
       if ((statbuffer.st_mode & S_IFMT) != S_IFREG) {
               fprintf(stderr, "%s: %s: can only touch regular files\n",
                       whoami, filename);
               return;
       }
       if (!access(filename,4|2)) {
               readwrite(filename,statbuffer.st_size);
               return;
       }
       if (force) {
               if (chmod(filename,0666)) {
                       fprintf(stderr, "%s: %s: couldn't chmod: ",
                               whoami, filename);
                       perror("");
                       return;
               }
               readwrite(filename,statbuffer.st_size);
               if (chmod(filename,statbuffer.st_mode)) {
                       fprintf(stderr, "%s: %s: couldn't chmod back: ",
                               whoami, filename);
                       perror("");
                       return;
               }
       } else {
               fprintf(stderr, "%s: %s: cannot touch\n", whoami, filename);
       }
}

readwrite(filename,size)
       char    *filename;
       int     size;
{
       int     filedescriptor;
       char    first;

       if (size) {
               filedescriptor = open(filename,2);
               if (filedescriptor == -1) {
error:
                       fprintf(stderr, "%s: %s: ", whoami, filename);
                       perror("");
                       return;
               }
               if (read(filedescriptor, &first, 1) != 1) {
                       goto error;
               }
               if (lseek(filedescriptor,0l,0) == -1) {
                       goto error;
               }
               if (write(filedescriptor, &first, 1) != 1) {
                       goto error;
               }
       } else {
               filedescriptor = creat(filename,0666);
               if (filedescriptor == -1) {
                       goto error;
               }
       }
       if (close(filedescriptor) == -1) {
               goto error;
       }
}