coreutils/chgrp.c

   1 /* @chgrp.c */
   2 #include <unistd.h>
   3 #include <stdio.h>
   4 #include <errno.h>
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <grp.h>
   8 #include <dirent.h>
   9 #include <string.h>
  10 #include <stdlib.h>
  11 #include <ctype.h>
  12
  13 int opt_h,
  14     opt_R,
  15     opt_HLP; /* 0: do not follow symlinks; 1: only for cmd args; 2: all */
  16 gid_t new_gid;
  17
  18 char *g_nam;
  19
  20 struct visited {
  21  struct visited *next;
  22  dev_t dev;
  23  ino_t ino;
  24 } *v_stack;
  25
  26 int add_visited(struct stat *s) {
  27  struct visited *v;
  28  if(!(v=malloc(sizeof(struct visited))))
  29   return 1;
  30  v->dev = s->st_dev;
  31  v->ino = s->st_ino;
  32  v->next = v_stack;
  33  if(v_stack)
  34   v_stack->next=v;
  35  else
  36   v_stack=v;
  37  return 0;
  38 }
  39
  40 int del_visited() {
  41  if(v_stack) {
  42   struct visited *v = v_stack->next;
  43   free(v_stack);
  44   v_stack=v;
  45   return 0;
  46  }
  47  return 1;
  48 }
  49
  50 int is_visited(struct stat *s) {
  51  struct visited *v=v_stack;
  52  while(v) {
  53   if(v->dev==s->st_dev && v->ino==s->st_ino)
  54    return 1;
  55   v=v->next;
  56  }
  57  return 0;
  58 }
  59
  60 /* chgrp everything in directory pointed to by path (and recurse, per opt_R and opt_HLP) */
  61 int do_chgrp(char *path) {
  62  DIR *cur;
  63  struct dirent *cur_file;
  64  struct stat f_stat;
  65  char *filename;
  66  int ret=0;
  67
  68  if(stat(path,&f_stat)) {
  69   fprintf(stderr,"%s: cannot stat %s: %s\n",g_nam,path,strerror(errno));
  70   return 1;
  71  }
  72  if(chdir(path)) {
  73   fprintf(stderr,"%s: cannot enter directory %s\n",g_nam,path);
  74   return 1;
  75  }
  76  if(add_visited(&f_stat)) {
  77   fprintf(stderr,"%s: cannot add path to stack: %s\n",g_nam,strerror(errno));
  78   return 1;
  79  }
  80  if(!(cur=opendir("."))) {
  81   fprintf(stderr,"%s: cannot open directory %s\n",g_nam,path);
  82   ret=1;
  83   goto enter_parent;
  84  }
  85  while(cur_file=readdir(cur)) {
  86   filename=cur_file->d_name;
  87   if(!strcmp(filename,".") || !strcmp(filename,".."))
  88    continue;
  89   if((opt_h)?lchown(filename,-1,new_gid):chown(filename,-1,new_gid)) {
  90    fprintf(stderr,"%s: cannot change group of %s: %s\n",g_nam,filename,strerror(errno));
  91    ret=1;
  92    continue;
  93   }
  94   if(opt_R) {
  95    if(lstat(filename,&f_stat)) {
  96    stat_fail:
  97     fprintf(stderr,"%s: cannot stat %s: %s\n",g_nam,filename,strerror(errno));
  98     ret=1;
  99     continue;
 100    }
 101    switch(f_stat.st_mode&S_IFMT) {
 102    case S_IFLNK:
 103     /* check if symlink points to directory... */
 104     if(stat(filename,&f_stat))
 105      goto stat_fail;
 106     if(f_stat.st_mode!=S_IFDIR)
 107      break;
 108     /* fall through and enter directory */
 109    case S_IFDIR:
 110     if(opt_HLP<2 || is_visited(&f_stat))
 111      break;
 112     ret|=do_chgrp(filename);
 113     break;
 114    default:
 115     break;
 116    }
 117   }
 118  }
 119  ret|=closedir(cur);
 120  enter_parent:
 121  del_visited();
 122  if(chdir("..")) {
 123   fprintf(stderr,"%s: cannot return to parent of %s: %s\n",g_nam,path,strerror(errno));
 124   return 1;
 125  }
 126  return ret;
 127 }
 128
 129 int main(int argc, char **argv) {
 130  int c;
 131  struct group *new_group;
 132  struct stat f_stat;
 133  char *path;
 134
 135  g_nam=argv[0];
 136  while((c=getopt(argc,argv,"hHLPR"))!=-1) {
 137   switch(c) {
 138    case 'h': /* chgrp symlink regular files and not its destination */
 139     opt_h=1;
 140     break;
 141    case 'H': /* enter only symlinked directories as args */
 142     opt_HLP=1;
 143     break;
 144    case 'L': /* enter all symlinked directories */
 145     opt_HLP=2;
 146     break;
 147    case 'P': /* do not enter symlinked directories */
 148     opt_HLP=0;
 149     break;
 150    case 'R': /* recurse */
 151     opt_R=1;
 152     break;
 153    case '?':
 154     fprintf(stderr,"%s: invalid option %c\n",argv[0],optopt);
 155     goto do_usage;
 156   }
 157  }
 158  if(!argv[optind]) {
 159   do_usage:
 160   fprintf(stderr,"usage: %s [-hR] group file ...\n       %s -R [-H | -L | -P] group file ...\n",argv[0],argv[0]);
 161   return 1;
 162  }
 163  if(!isdigit(argv[optind][0])) {
 164   if(!(new_group=getgrnam(argv[optind++]))) {
 165    fprintf(stderr,"%s: invalid group %s\n",argv[0],argv[optind-1]);
 166    return 2;
 167   }
 168   new_gid=new_group->gr_gid;
 169  } else
 170   new_gid=atoi(argv[optind++]);
 171  c=0;
 172  while(path=argv[optind++]) { /* main chown loop */
 173   if((opt_h)?lchown(path,-1,new_gid):chown(path,-1,new_gid)) {
 174    fprintf(stderr,"%s: cannot change group of %s: %s\n",argv[0],path,strerror(errno));
 175    c=1;
 176    continue;
 177   }
 178   if(opt_R) { /* recurse if a subdirectory */
 179    if(lstat(path,&f_stat)) {
 180    stat_fail:
 181     fprintf(stderr,"%s: cannot stat %s: %s\n",argv[0],path,strerror(errno));
 182     c=1;
 183     continue;
 184    }
 185    switch(f_stat.st_mode&S_IFMT) {
 186    case S_IFLNK:
 187     if(!opt_HLP) /* do not follow any symlinks */
 188      break;
 189     /* check if symlink points to directory... */
 190     if(stat(path,&f_stat))
 191      goto stat_fail;
 192     if(f_stat.st_mode!=S_IFDIR)
 193      break;
 194     /* fall through and enter directory */
 195    case S_IFDIR:
 196     c|=do_chgrp(path);
 197     break;
 198    default:
 199     break;
 200    }
 201   }
 202  }
 203  return c;
 204 }