/* Name: tail()
*
* Description:
*
* This function displays the last lines at the end of a file in an ext2
* file system.
*
* Algorithm:
*
* Get the directory and basename of the file
* Determine the inode number for the file
* Open the file for reading
* Skip to the last block in the file
* While we have not found the last num_lines of newline characters
* Skip backwards in the file one block and read it
* Display the contents of the block from that point on.
* Display the rest of the file if not contained in the block
* Save the current location of the file.
* If we are following the file as it grows
* While forever
* Sleep
* Re-read the inode for the file
* If the size has changed
* Display the file from the saved point on
* Save the current location of the file.
*
*
* Global Variables:
*
* None
*
* Arguments:
*
* ext2_filsys *fs; Our filesystem
* ext2_ino_t root; The root directory inode number
* char *input; The name of the input file to tail
* int num_lines; The number of lines to display
* int follow; Flag indicating if the we should follow any
* new contents to the file.
* int sleep_int; The number of seconds to sleep between checking
* for new lines
* char *cur_filesys
*
* Return Values:
*
* 0 - the last number of lines was displayed correctly.
* an error occurred.
*
* Author: Keith W. Sheffield
* Date: 08/07/2002
*
* Modification History:
*
* MM/DD/YY Name Description
*/
static long
tail(ext2_filsys *fs_ptr, ext2_ino_t root, char *input, int num_lines,
int follow, int sleep_int, char *cur_filesys)
{
ext2_filsys fs = *fs_ptr;
ext2_ino_t cwd;
ext2_ino_t tail_ino;
ext2_ino_t t_tail_ino;
char *tail_dir;
char *tail_name;
long retval;
char buf[BLK_SIZE];
unsigned int bytes_to_read;
unsigned int bytes_read;
char *ptr;
struct ext2_inode inode;
ext2_file_t tail_fd;
ext2_off_t offset;
ext2_off_t cur_pos;
if (get_file_parts(fs, root, input, &cwd, &tail_dir, &tail_name))
{
ext2fs_close(fs);
return(-1);
}
/* get the inode number for the source file */
if ((retval = ext2fs_namei(fs, cwd, cwd, tail_name, &tail_ino)))
{
fprintf(stderr, "%s: file %s\n",error_message(retval),
tail_name);
return(retval);
}
/* open the file */
if ((retval = ext2fs_file_open(fs, tail_ino, 0, &tail_fd)))
{
fputs(error_message(retval), stderr);
return retval;
}
/* get the length of the file and determine where to start reading */
inode.i_size = offset = ext2fs_file_get_size(tail_fd);
bytes_to_read = offset % BLK_SIZE;
if (bytes_to_read == 0)
bytes_to_read = BLK_SIZE;
offset -= bytes_to_read;
if (((int32_t)offset) < 0)
offset = 0;
do
{
/* seek to the start of the last block in the file */
if ((retval = ext2fs_file_lseek(tail_fd, offset, EXT2_SEEK_SET, NULL)))
{
fputs(error_message(retval), stderr);
return retval;
}
/* read the last block in the file */
if ((retval = ext2fs_file_read(tail_fd, buf, bytes_to_read,
&bytes_read)))
{
fputs(error_message(retval), stderr);
return retval;
}
if (bytes_to_read != bytes_read)
{
fputs("error reading file\n", stderr);
return(-1);
}
ptr = buf + bytes_read - 1;
while (bytes_to_read--)
{
if (*ptr == '\n' && num_lines-- == 0)
{
/* if the newline wasn't the last character in the buffer, then
* print what's remaining.
*/
if (bytes_to_read != bytes_read - 1)
{
ptr++;
if (0 > write(1, ptr, bytes_read - bytes_to_read - 1))
{
perror("writing bytes to stdout");
return -1;
}
}
offset = 0; /* make sure we break out of the main loop */
break;
}
ptr--;
}
offset -= (offset < BLK_SIZE) ? offset : BLK_SIZE;
bytes_to_read = BLK_SIZE;
}
while (offset > 0);
/* if we are here and have any lines left, we hit the beginning, so
* dump the rest of what's in memory out.
*/
if (num_lines > 0)
{
if (0 > write(1, buf, bytes_read)) {
perror("writing bytes to stdout");
return -1;
}
}
/* retreive the current position in the file */
if ((retval = ext2fs_file_lseek(tail_fd, 0, EXT2_SEEK_CUR, &cur_pos)))
{
fputs(error_message(retval), stderr);
return retval;
}
/* ok, if we are before the end of the file, then dump the rest of it */
if (cur_pos < inode.i_size)
{
if ((retval = read_to_eof(tail_fd, 1, cur_pos, &cur_pos)))
{
return retval;
}
}
if ((retval = ext2fs_file_close(tail_fd)))
{
fputs(error_message(retval), stderr);
return retval;
}
if (follow)
{
while(1)
{
sleep(sleep_int);
/* I don't know how to force a re-read of the file system info yet,
* so, just close the file system and reopen it.
*/
ext2fs_close(fs);
if ((retval = open_filesystem(cur_filesys, &fs, &root, 0)))
{
*fs_ptr = NULL;
fprintf(stderr, "%s: %s\n", error_message(retval), cur_filesys);
return retval;
}
*fs_ptr = fs;
/* if we are following the name, find the directory and file name
* again.
*/
if (follow == FOLLOW_NAME)
{
cwd = root;
if (tail_dir != NULL && *tail_dir != '\0' &&
strcmp(tail_dir, ",") != 0 &&
(retval = change_cwd(fs, root, &cwd, tail_dir)))
{
fprintf(stderr, "Error changing to directory %s\n",
tail_dir);
return(retval);
}
/* get the inode number for the source file */
if ((retval = ext2fs_namei(fs, cwd, cwd, tail_name,
&t_tail_ino)))
{
fprintf(stderr, "%s: file %s\n",error_message(retval),
tail_name);
return(retval);
}
/* if we are dealing with a new file, then start from the
* beginning.
*/
if (t_tail_ino != tail_ino)
{
tail_ino = t_tail_ino;
cur_pos = 0;
}
}
if ((retval = ext2fs_read_inode(fs, tail_ino, &inode)))
{
fputs(error_message(retval), stderr);
return retval;
}
if (inode.i_size > cur_pos)
{
if ((retval = retrieve_data(fs, tail_ino, 1, NULL, 0, cur_pos,
&cur_pos)))
{
fputs(error_message(retval), stderr);
return retval;
}
}
else if (inode.i_size < cur_pos)
{
/* the file was truncated, so bail */
return(0);
}
}
}
return(0);
}
/* Name: do_mv()
*
* Description:
*
* This function reads the command line arguments and moves or renames files
* in an ext2fs file system
*
* Algorithm:
*
* Read any command line switches
* Get the first source file specification
* If we are performing a file swap, call do_swap()
* Open the file system
* Get the destination and determine if it is a directory
* If not, then get the destination's directory and basename
* Also check that the number of source files are no more than one
* For each source file
* Get the directory and basename of the source file
* Determine the inode number for the source file
* Create the link
* Unlink the original source file.
*
* Global Variables:
*
* None
*
* Arguments:
*
* int argc; The number of arguments
* char *argv[]; The command line arguments
*
* Return Values:
*
* 0 - the file was move successfully
* an error occurred.
*
* Author: Keith W. Sheffield
* Date: 03/20/2002
*
* Modification History:
*
* MM/DD/YY Name Description
*/
long
do_mv(int argc, char *argv[])
{
int verbose=0;
int force=0;
int swap_files=0;
int errcnt=0;
char *cur_filesys = NULL;
ext2_filsys fs = NULL;
ext2_ino_t root;
ext2_ino_t srcd;
ext2_ino_t destd;
ext2_ino_t source_file;
char *src_dir;
char *dest_dir;
char *src_name;
char *dest_name;
char *result_name;
long retval;
int c;
int curidx;
#ifdef HAVE_OPTRESET
optreset = 1; /* Makes BSD getopt happy */
#endif
while ((c = getopt(argc, argv, "vfs")) != EOF)
{
switch (c)
{
case 'v':
verbose = 1;
break;
case 'f':
force = E2T_FORCE;
break;
case 's':
swap_files = 1;
break;
default:
errcnt++;
break;
}
}
curidx = optind;
force |= E2T_DO_MV;
if (errcnt || argc < curidx+2)
{
fputs(USAGE, stderr);
return(1);
}
if (swap_files)
return(do_swap(force, verbose, curidx, argc, argv));
cur_filesys = argv[curidx++];
if (NULL == (src_dir = strchr(cur_filesys, ':')))
{
fprintf(stderr, "Invalid file specification: %s\n", cur_filesys);
return(1);
}
*src_dir++ = '\0';
if ((retval = open_filesystem(cur_filesys, &fs, &root, 1)))
{
return retval;
}
/* get the destination directory */
dest_name = NULL;
if (strcmp(dest_dir = argv[argc-1], ".") != 0)
{
/* check to see if the file name already exists in the current
* directory and also see if it is a directory.
*/
if ((retval = ext2fs_namei(fs, root, root, dest_dir, &destd)) ||
(retval = ext2fs_check_directory(fs, destd)))
{
if (retval != EXT2_ET_FILE_NOT_FOUND &&
retval != EXT2_ET_NO_DIRECTORY)
{
fprintf(stderr, "%s\n",error_message(retval));
ext2fs_close(fs);
return(retval);
}
/* ok, so it's either not there or it's not a directory, so
* get the real destination directory and file name.
*/
if (curidx+1 < argc)
{
fprintf(stderr, "%s must be a directory!\n", dest_dir);
ext2fs_close(fs);
return(1);
}
if (get_file_parts(fs, root, dest_dir, &destd, &dest_dir,
&dest_name))
{
ext2fs_close(fs);
return(-1);
}
}
else /* we have a directory!!! */
dest_name = NULL;
}
else
{
destd = root;
dest_name = NULL;
}
do
{
/* move to the source directory */
if (get_file_parts(fs, root, src_dir, &srcd, &src_dir, &src_name))
{
ext2fs_close(fs);
return(-1);
}
/* get the inode number for the source file */
if ((retval = ext2fs_namei(fs, srcd, srcd, src_name, &source_file)))
{
fprintf(stderr, "%s: source file %s\n",error_message(retval),
src_name);
ext2fs_close(fs);
return(retval);
}
result_name = (dest_name) ? dest_name : src_name;
/* now create the link */
if ((retval = create_hard_link(fs, destd, source_file, result_name,
force)))
{
fprintf(stderr, "Error renaming %s/%s as %s/%s\n",
((src_dir == NULL) ? "." : src_dir), src_name,
((dest_dir == NULL) ? "." : dest_dir), result_name);
ext2fs_close(fs);
return(1);
}
if ((retval = ext2fs_unlink(fs, srcd, src_name, 0, 0)))
{
fprintf(stderr, "%s - %s\n", src_name, error_message(retval));
ext2fs_close(fs);
return(retval);
}
if (verbose)
fprintf(stderr, "moved %s/%s as %s/%s\n",
((src_dir == NULL) ? "." : src_dir), src_name,
((dest_dir == NULL) ? "." : dest_dir), result_name);
src_dir = argv[curidx++];
}
while (curidx < argc);
ext2fs_close(fs);
return(0);
} /* end of do_mv */
/* Name: do_ln()
*
* Description:
*
* This function reads the command line arguments and creates a link
* in an ext2fs file system
*
* Algorithm:
*
* Read any command line switches
* Get the source file specification
* Open the file system
* Get the directory and basename of the source file
* Determine the inode number for the source file
* If the destination file is not given or if it's a .
* use the current directory and the basename of the source file
* Otherwise
* Get the directory and basename of the destination file
* Create the link
*
* Global Variables:
*
* None
*
* Arguments:
*
* int argc; The number of arguments
* char *argv[]; The command line arguments
*
* Return Values:
*
* 0 - the link was created successfully
* an error occurred.
*
* Author: Keith W. Sheffield
* Date: 03/05/2002
*
* Modification History:
*
* MM/DD/YY Name Description
* 03/06/02 K. Sheffield Modified to perform file moves
* 03/20/02 K. Sheffield Moved the mv operation to a separate file
*/
long
do_ln(int argc, char *argv[])
{
int verbose=0;
int force=0;
int symlink=0;
int errcnt=0;
char *cur_filesys = NULL;
ext2_filsys fs = NULL;
ext2_ino_t root;
ext2_ino_t srcd;
ext2_ino_t destd;
ext2_ino_t source_file;
char *src_dir;
char *dest_dir;
char *src_name;
char *dest_name;
long retval;
int c;
#ifdef HAVE_OPTRESET
optreset = 1; /* Makes BSD getopt happy */
#endif
while ((c = getopt(argc, argv, "vfs")) != EOF)
{
switch (c)
{
case 'v':
verbose = 1;
break;
case 'f':
force = E2T_FORCE;
break;
case 's':
symlink = 1;
break;
default:
errcnt++;
break;
}
}
if (errcnt || argc == optind)
{
fputs(USAGE, stderr);
return(1);
}
if (symlink)
{
fputs("Not implemented yet\n", stderr);
return(1);
}
cur_filesys = argv[optind++];
if (NULL == (src_dir = strchr(cur_filesys, ':')))
{
fprintf(stderr, "Invalid file specification: %s\n", cur_filesys);
return(1);
}
*src_dir++ = '\0';
if (*src_dir == '\0')
{
fputs(USAGE, stderr);
return(1);
}
if ((retval = open_filesystem(cur_filesys, &fs, &root, 1)))
{
fprintf(stderr, "%s: %s\n", error_message(retval), cur_filesys);
return retval;
}
/* move to the source directory */
if (get_file_parts(fs, root, src_dir, &srcd, &src_dir, &src_name))
{
ext2fs_close(fs);
return(-1);
}
/* get the inode number for the source file */
if ((retval = ext2fs_namei(fs, srcd, srcd, src_name, &source_file)))
{
fprintf(stderr, "%s: source file %s\n",error_message(retval), src_name);
ext2fs_close(fs);
return(retval);
}
/* get the destination directory */
destd = root;
if (argc == optind || strcmp(dest_dir = argv[optind], ".") == 0)
dest_name = src_name;
else
{
if (get_file_parts(fs, root, dest_dir, &destd, &dest_dir,
&dest_name))
{
ext2fs_close(fs);
return(-1);
}
}
/* now create the link */
if ((retval = create_hard_link(fs, destd, source_file, dest_name, force)))
{
fprintf(stderr, "Error linking %s/%s as %s/%s\n",
((src_dir == NULL) ? "." : src_dir), src_name,
((dest_dir == NULL) ? "." : dest_dir), dest_name);
ext2fs_close(fs);
return(1);
}
if (verbose)
fprintf(stderr, "linked %s/%s as %s/%s\n",
((src_dir == NULL) ? "." : src_dir), src_name,
((dest_dir == NULL) ? "." : dest_dir), dest_name);
ext2fs_close(fs);
return(0);
} /* end of do_ln */
static long
do_swap(int force, int verbose, int curidx, int argc, char **argv)
{
char *cur_filesys = NULL;
ext2_filsys fs = NULL;
ext2_ino_t root;
ext2_ino_t file1_dirno;
ext2_ino_t file2_dirno;
ext2_ino_t file3_dirno;
ext2_ino_t file1_no;
ext2_ino_t file2_no;
char *file1_dir;
char *file2_dir;
char *file3_dir;
char *file1_name;
char *file2_name;
char *file3_name;
long retval;
if (curidx + 2 > argc)
{
fputs(USAGE, stderr);
return(1);
}
cur_filesys = argv[curidx++];
if (NULL == (file1_dir = strchr(cur_filesys, ':')))
{
fprintf(stderr, "Invalid file specification: %s\n", cur_filesys);
return(1);
}
*file1_dir++ = '\0';
if ((retval = open_filesystem(cur_filesys, &fs, &root, 1)))
{
return retval;
}
/* move to the file 1 directory */
if (get_file_parts(fs, root, file1_dir, &file1_dirno, &file1_dir,
&file1_name))
{
ext2fs_close(fs);
return(-1);
}
/* get the inode number for the file 1 file */
if ((retval = ext2fs_namei(fs, file1_dirno, file1_dirno, file1_name,
&file1_no)))
{
fprintf(stderr, "%s: file 1 file %s\n",error_message(retval),
file1_name);
ext2fs_close(fs);
return(retval);
}
/* move to the file 2 directory */
if (get_file_parts(fs, root, argv[curidx++], &file2_dirno, &file2_dir,
&file2_name))
{
ext2fs_close(fs);
return(-1);
}
/* get the inode number for the file 2 file */
if ((retval = ext2fs_namei(fs, file2_dirno, file2_dirno, file2_name,
&file2_no)))
{
fprintf(stderr, "%s: file 2 file %s\n",error_message(retval),
file2_name);
ext2fs_close(fs);
return(retval);
}
if (curidx < argc)
{
/* move to the file 3 directory */
if (get_file_parts(fs, root, argv[curidx++], &file3_dirno, &file3_dir,
&file3_name))
{
ext2fs_close(fs);
return(-1);
}
/* now move the first file to the 3rd */
if ((retval = create_hard_link(fs, file3_dirno, file1_no, file3_name,
force)))
{
fprintf(stderr, "Error renaming %s/%s as %s/%s\n",
((file1_dir == NULL) ? "." : file1_dir), file1_name,
((file3_dir == NULL) ? "." : file3_dir), file3_name);
ext2fs_close(fs);
return(1);
}
if ((retval = ext2fs_unlink(fs, file1_dirno, file1_name, 0, 0)))
{
fprintf(stderr, "%s - %s\n", file1_name, error_message(retval));
ext2fs_close(fs);
return(retval);
}
/* now move the 2nd file to the 1st */
if ((retval = create_hard_link(fs, file1_dirno, file2_no, file1_name,
force)))
{
fprintf(stderr, "Error renaming %s/%s as %s/%s\n",
((file2_dir == NULL) ? "." : file2_dir), file2_name,
((file1_dir == NULL) ? "." : file1_dir), file1_name);
ext2fs_close(fs);
return(1);
}
if ((retval = ext2fs_unlink(fs, file2_dirno, file2_name, 0, 0)))
{
fprintf(stderr, "%s - %s\n", file2_name, error_message(retval));
ext2fs_close(fs);
return(retval);
}
if (verbose)
fprintf(stderr, "renamed file %s/%s as %s/%s\n"
"renamed file %s/%s as %s/%s\n",
((file1_dir == NULL) ? "." : file1_dir), file1_name,
((file3_dir == NULL) ? "." : file3_dir), file3_name,
((file2_dir == NULL) ? "." : file2_dir), file2_name,
((file1_dir == NULL) ? "." : file1_dir), file1_name);
}
else
{
/* now remove the first file */
if ((retval = ext2fs_unlink(fs, file1_dirno, file1_name, 0, 0)))
{
fprintf(stderr, "%s - %s\n", file1_name, error_message(retval));
ext2fs_close(fs);
return(retval);
}
/* now move the 2nd file to the 1st */
if ((retval = create_hard_link(fs, file1_dirno, file2_no, file1_name,
force)))
{
fprintf(stderr, "Error renaming %s/%s as %s/%s\n",
((file2_dir == NULL) ? "." : file2_dir), file2_name,
((file1_dir == NULL) ? "." : file1_dir), file1_name);
ext2fs_close(fs);
return(1);
}
if ((retval = ext2fs_unlink(fs, file2_dirno, file2_name, 0, 0)))
{
fprintf(stderr, "%s - %s\n", file2_name, error_message(retval));
ext2fs_close(fs);
return(retval);
}
if ((retval = create_hard_link(fs, file2_dirno, file1_no, file2_name,
force)))
{
fprintf(stderr, "Error renaming %s/%s as %s/%s\n",
((file1_dir == NULL) ? "." : file1_dir), file1_name,
((file2_dir == NULL) ? "." : file2_dir), file2_name);
ext2fs_close(fs);
return(1);
}
if (verbose)
fprintf(stderr, "swapped files %s/%s <-> %s/%s\n",
((file1_dir == NULL) ? "." : file1_dir), file1_name,
((file2_dir == NULL) ? "." : file2_dir), file2_name);
}
ext2fs_close(fs);
return(0);
} /* end of do_swap */
