diff options
Diffstat (limited to 'libc/pwd_grp/__getgrent.c')
| -rw-r--r-- | libc/pwd_grp/__getgrent.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/libc/pwd_grp/__getgrent.c b/libc/pwd_grp/__getgrent.c new file mode 100644 index 000000000..612f1124d --- /dev/null +++ b/libc/pwd_grp/__getgrent.c @@ -0,0 +1,168 @@ +/* + * __getgrent.c - This file is part of the libc-8086/grp package for ELKS, + * Copyright (C) 1995, 1996 Nat Friedman <ndf@linux.mit.edu>. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <grp.h> +#include "config.h" + +/* + * This is the core group-file read function. It behaves exactly like + * getgrent() except that it is passed a file descriptor. getgrent() + * is just a wrapper for this function. + */ +struct group * +__getgrent(int grp_fd) +{ +#ifndef GR_SCALE_DYNAMIC + static char line_buff[GR_MAX_LINE_LEN]; + static char * members[GR_MAX_MEMBERS]; +#else + static char * line_buff = NULL; + static char ** members = NULL; + short line_index; + short buff_size; +#endif + static struct group group; + register char * ptr; + char * field_begin; + short member_num; + char * endptr; + int line_len; + + + /* We use the restart label to handle malformatted lines */ +restart: +#ifdef GR_SCALE_DYNAMIC + line_index=0; + buff_size=256; +#endif + +#ifndef GR_SCALE_DYNAMIC + /* Read the line into the static buffer */ + if ((line_len=read(grp_fd, line_buff, GR_MAX_LINE_LEN))<=0) + return NULL; + field_begin=strchr(line_buff, '\n'); + if (field_begin!=NULL) + lseek(grp_fd, (long) (1+field_begin-(line_buff+line_len)), SEEK_CUR); + else /* The line is too long - skip it :-\ */ + { + do { if ((line_len=read(grp_fd, line_buff, GR_MAX_LINE_LEN))<=0) + return NULL; + } while (!(field_begin=strchr(line_buff, '\n'))); + lseek(grp_fd, (long) ((field_begin-line_buff)-line_len+1), SEEK_CUR); + goto restart; + } + if (*line_buff=='#' || *line_buff==' ' || *line_buff=='\n' || + *line_buff=='\t') + goto restart; + *field_begin='\0'; + +#else /* !GR_SCALE_DYNAMIC */ + line_buff=realloc(line_buff, buff_size); + while (1) + { + if ((line_len=read(grp_fd, line_buff+line_index, + buff_size-line_index))<=0) + return NULL; + field_begin=strchr(line_buff, '\n'); + if (field_begin!=NULL) + { + lseek(grp_fd, (long) (1+field_begin-(line_len+line_index+line_buff)), + SEEK_CUR); + *field_begin='\0'; + if (*line_buff=='#' || *line_buff==' ' || *line_buff=='\n' || + *line_buff=='\t') + goto restart; + break; + } + else /* Allocate some more space */ + { + line_index=buff_size; + buff_size+=256; + line_buff=realloc(line_buff, buff_size); + } + } +#endif /* GR_SCALE_DYNAMIC */ + + /* Now parse the line */ + group.gr_name=line_buff; + ptr=strchr(line_buff, ':'); + if (ptr==NULL) goto restart; + *ptr++='\0'; + + group.gr_passwd=ptr; + ptr=strchr(ptr, ':'); + if (ptr==NULL) goto restart; + *ptr++='\0'; + + field_begin=ptr; + ptr=strchr(ptr, ':'); + if (ptr==NULL) goto restart; + *ptr++='\0'; + + group.gr_gid=(gid_t) strtoul(field_begin, &endptr, 10); + if (*endptr!='\0') goto restart; + + member_num=0; + field_begin=ptr; + +#ifndef GR_SCALE_DYNAMIC + while ((ptr=strchr(ptr, ','))!=NULL) + { + *ptr='\0'; + ptr++; + members[member_num]=field_begin; + field_begin=ptr; + member_num++; + } + if (*field_begin=='\0') + members[member_num]=NULL; + else + { + members[member_num]=field_begin; + members[member_num+1]=NULL; + } +#else /* !GR_SCALE_DYNAMIC */ + if (members!=NULL) + free (members); + members=(char **) malloc(1*sizeof(char *)); + while ((ptr=strchr(ptr, ','))!=NULL) + { + *ptr='\0'; + ptr++; + members[member_num]=field_begin; + field_begin=ptr; + member_num++; + members=(char **)realloc((void *)members, (member_num+1)*sizeof(char *)); + } + if (*field_begin=='\0') + members[member_num]=NULL; + else + { + members[member_num]=field_begin; + members[member_num+1]=NULL; + } +#endif /* GR_SCALE_DYNAMIC */ + + group.gr_mem=members; + return &group; +} |