pjht/ext2_parser
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More work. Can read files and change directories now.

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This commit is contained in:
pjht 2018-11-12 07:49:10 -06:00
parent 66cb5cf441
commit 54d9ce66e6
2 changed files with 75 additions and 40 deletions
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ext2.img
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115
main.c
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@ -149,6 +149,7 @@ char** get_dir_listing(uint32_t inode_num) {
} }
names[num_entries_used]=malloc(current_entry->name_len+1); names[num_entries_used]=malloc(current_entry->name_len+1);
strcpy(names[num_entries_used],current_entry->file_name); strcpy(names[num_entries_used],current_entry->file_name);
names[num_entries_used][current_entry->name_len]='\0';
num_entries_used++; num_entries_used++;
tot_size+=current_entry->rec_len; tot_size+=current_entry->rec_len;
current_entry=(dir_entry*)(((uint64_t)current_entry)+current_entry->rec_len); current_entry=(dir_entry*)(((uint64_t)current_entry)+current_entry->rec_len);
@ -189,6 +190,38 @@ dir_entry* read_dir_entry(uint32_t inode_num,uint32_t dir_entry_num) {
return NULL; return NULL;
} }
uint32_t inode_for_fname(uint32_t dir_inode_num, char* name, char* got_inode) {
uint32_t inode=0;
*got_inode=0;
char** names=get_dir_listing(dir_inode_num);
for(int i=0;names[i]!=NULL;i++) {
if (strcmp(names[i],name)==0) {
dir_entry* entry=read_dir_entry(dir_inode_num,i);
inode=entry->inode;
*got_inode=1;
break;
}
}
free_dir_listing(names);
return inode;
}
char* fname_for_inode(uint32_t dir_inode_num, uint32_t inode_num) {
for(int i=0;;i++) {
dir_entry* entry=read_dir_entry(dir_inode_num,i);
if (entry) {
if (entry->inode==inode_num) {
char* name=malloc(strlen(entry->file_name)+1);
strcpy(name,entry->file_name);
return name;
}
} else {
break;
}
}
return NULL;
}
int main() { int main() {
FILE* f=fopen("ext2.img","rb"); FILE* f=fopen("ext2.img","rb");
if (f) { if (f) {
@ -199,22 +232,20 @@ int main() {
blk_size=1024<<(supblk->s_log_blk_size); blk_size=1024<<(supblk->s_log_blk_size);
double num_blk_grps_dbl=supblk->s_blocks_count/(double)supblk->s_blocks_per_group; double num_blk_grps_dbl=supblk->s_blocks_count/(double)supblk->s_blocks_per_group;
uint32_t num_blk_grps=ceil(num_blk_grps_dbl); uint32_t num_blk_grps=ceil(num_blk_grps_dbl);
show_supblk_info(num_blk_grps); // show_supblk_info(num_blk_grps);
blk_grps=malloc(sizeof(blk_grp*)*num_blk_grps); blk_grps=malloc(sizeof(blk_grp*)*num_blk_grps);
blk_grp* blk_group=read_blk(2); blk_grp* blk_group=read_blk(2);
for (int i=0;i<num_blk_grps;i++) { for (int i=0;i<num_blk_grps;i++) {
printf("Block group %d:\n",i);
printf("Number of unallocated blocks:%d\n",blk_group->bg_free_blocks_count);
printf("Number of unallocated inodes:%d\n",blk_group->bg_free_inodes_count);
blk_grps[i]=blk_group; blk_grps[i]=blk_group;
blk_group++; blk_group++;
}; };
uint32_t cwi=2; uint32_t cwi=2;
while(1) { while(1) {
printf(">"); printf(">");
char cmd[256]; char line[256];
fgets(cmd,256,stdin); fgets(line,256,stdin);
cmd[strlen(cmd)-1]='\0'; line[strlen(line)-1]='\0';
char* cmd=strtok(line," ");
if (strcmp(cmd,"ls")==0) { if (strcmp(cmd,"ls")==0) {
char** names=get_dir_listing(cwi); char** names=get_dir_listing(cwi);
for(int i=0;names[i]!=NULL;i++) { for(int i=0;names[i]!=NULL;i++) {
@ -222,42 +253,46 @@ int main() {
} }
printf("\n"); printf("\n");
free_dir_listing(names); free_dir_listing(names);
} else { } else if (strcmp(cmd,"inode")==0) {
uint32_t inode; char* name=strtok(NULL," ");
char got_inode=0; char got_inode;
char** names=get_dir_listing(cwi); uint32_t inode=inode_for_fname(cwi,name,&got_inode);
for(int i=0;names[i]!=NULL;i++) {
if (strcmp(names[i],cmd)==0) {
dir_entry* entry=read_dir_entry(2,i);
inode=entry->inode;
got_inode=1;
break;
}
}
free_dir_listing(names);
if (got_inode) { if (got_inode) {
printf("Inode for %s:%d\n",cmd,inode); printf("Inode for %s:%d\n",name,inode);
} else { } else {
printf("No such file or directory %s\n",cmd); printf("inode: %s: No such file or directory\n",name);
} }
} else if (strcmp(cmd,"cd")==0) {
char* name=strtok(NULL," ");
char got_inode;
uint32_t inode_num=inode_for_fname(cwi,name,&got_inode);
if (got_inode) {
inode dir_inode=read_inode(inode_num);
if ((dir_inode.i_mode&EXT2_S_IFDIR)!=0) {
cwi=inode_num;
} else {
printf("cd: %s: Not a directory\n",name);
}
} else {
printf("cd: %s: No such file or directory\n",name);
}
} else if (strcmp(cmd,"pwi")==0) {
printf("%d\n",cwi);
} else if (strcmp(cmd,"cat")==0) {
char* name=strtok(NULL," ");
char got_inode;
uint32_t inode_num=inode_for_fname(cwi,name,&got_inode);
if (got_inode) {
inode file_inode=read_inode(inode_num);
char* contents=read_blk(file_inode.i_block[0]);
printf("%s",contents);
} else {
printf("type: %s: No such file or directory\n",name);
}
} else if (strcmp(cmd,"quit")==0) {
exit(0);
} else {
printf("%s: Comand not found\n",cmd);
} }
} }
// printf("lost+found:\n");
// inode lost_dir_inode=read_inode(11);
// show_inode_info(lost_dir_inode);
// printf("Block:%d\n",lost_dir_inode.i_block[0]);
// dir_entry* lost_dir=read_blk(lost_dir_inode.i_block[0]);
// current_entry=lost_dir;
// for(int i=0;;i++) {
// if (current_entry->file_type==0) {
// break;
// }
// printf("Directory entry %d:\n",i);
// printf("Directory entry inode:%d\n",current_entry->inode);
// printf("Length of entry:%d\n",current_entry->rec_len);
// printf("Length of name:%d\n",current_entry->name_len);
// printf("File type:%d\n",current_entry->file_type);
// printf("File name:%s\n",(char*)current_entry+sizeof(dir_entry));
// current_entry=(dir_entry*)(((uint64_t)current_entry)+current_entry->rec_len);
// }
} }