| cd [directory] | S |
| Change the current directory. Without argument changes to home directory. cd - changes to previous directory. | |
| chgrp [-Rfv] group file[s] | |
| Change the group ownership of files | Documentation |
| chmod [-Rfv] mode file[s] | |
| Change the access permissions of files. Mode can be an (octal) value where the 3 rightmost digits ugo denote user, group and other's permissions and the bits in the digit stand for read (4), write (2) and execute (1) permission. | Documentation |
| Example: 710 sets all permissions for the owner and execute for group. Mode can also be a string of letters (ugoa for user, group, others or all) followed by an operator +-= to add, take away or assign permissions followed by the permissions rwx for read, write and execute. Example: g+w adds group write permissions to the file[s]. Beware: on AFS file systems only the user permissions are respected. For setting access rights in AFS see fs. | Documentation |
| chown [-Rfv] [user][:group] file[s] | |
| Change the user (and group) ownership of files. | Documentation |
| cp [-Rfipuv] source destination | |
| cp [-Rfipuv] source[s] directory | |
| Copy files. With -p preserve owner, group and time stamps in the copied file[s]. -u copies only newer or missing source files | Documentation |
| cp -a [-fiulsLx] sourcedir targetdir | |
| Copy files recursively, i.e. a whole directory tree. -a is equivalent to -dpR. Look up the meaning of -l, -s, -L and -x for influencing the copy process. | Documentation |
| cpd | AZ |
| Change to a directory previously visited. | |
| df [-k] [file[s]] | |
| Displays free disk space in blocks (-k in kbytes) of all mounted file systems or of the file systems where file[s] are found. For AFS see fs. | Documentation |
| du [-ks] [dir[s]] | |
| Summarize disk usage in units of disk blocks (-k in kbytes). With -s display only the grand total, otherwise report recursively on each directory. | Documentation |
| groups [username[s]] | |
| Print the groups a user is in | Documentation |
| id [-gGnru] [username] | |
| Print real (-r) and effective user (-u) and group (-gG) IDs or names (-n) for the current user or username. Prints all the information if no options given. | Documentation |
| ll [option[s]] [file[s]] | A |
| Shorthand for ls -l. Additional options as for ls can be given. | |
| ln [-fisv] file new_name | |
| ln [-fisv] dir[s] new_directory_name | |
| Make links between files. Hard links can be established within a file system only (not within AFS). Symlinks (with -s) are more flexible and visible. | Documentation |
| ls [-abcdFlLnrRStu] [file[s]] | A |
| List contents of directories. The most frequently used options are -a list all entries, including those starting with a dot (.) -b print octal escapes for nongraphic characters -c use time of last inode modification (with -l, -n and -t) -d if the argument is a directory, list only its name, not its contents -F append /, * and @ to filename for dirs, executables and symlinks resp. -l list in long format (mode, number of links, owner, group, size, time) -L if the argument is a symbolic link, list the file it is pointing to -n like -l, but display UID and GID instead of owner and group -r reverse order of sort (alphabetic or by time) -R recursively list subdirectories -S sort by file size -t sort by time instead of by name (default: last file modification time) -u use time of last access (with -l, -n and -t) ls is usually aliased to ls --color=tty to distinguish file types by color. The alias (like all aliases) gets suppressed by prefixing it with backslash: \ls | Documentation |
| lsize [directory] | AZ |
| List the 20 largest files in a directory. This is similar to ls -lS. | |
| lt [option[s]] [file[s]] | A |
| List contents of directories by file modification time (long form). Similar to ls -lt. Additional options as for ls can be given. Only the 20 newest files are printed. Useful also in conjunction with options -r (display the oldest files), -u (sort by access time) and -c (sort by inode modification time). | |
| mkdir [-p] [-m mode] dir[s] | |
| Make directories. With -p a directory hierarchy can be created. The permission mode can be set simultaneously | Documentation |
| mv [-fiv] source destination | |
| mv [-fiv] source[s] directory | |
| Rename source file to destination file or move source files[s] into directory. | Documentation |
| newgrp [group] | |
| Change group ID to group or back to group in passwd entry if no group is given. Each call of newgrp opens a new shell like login does. | |
| pwd | S |
| Print name of current/working directory | Documentation |
| quota [-v] [username] | MZ |
| Display disk usage and limits. Hamburg: Does not work for AFS, please see fs listquota. Zeuthen: System command replaced by a script to report quota on all AFS volumes belonging to the current user or username, not only on home dir. To identify files for removal the commands du, lsize, lt -r, lt -ru, find and locate are useful. | |
| rm [-fiv] file[s] | |
| rm -rR [-fiv] dir[s] | |
| Remove files (or for -r or -R whole directory trees). | Documentation |
| rmdir [-p] dir[s] | |
| Remove empty directories (and with -p its empty parent dirs as well) | Documentation |
| rsync [-ah] source destination | |
| Fast remote file copy. Option -h outputs usage information. Allows to synchronize remote and local directories. Uses ssh by default. The arguments are of the form [[user@]host:]filename. The most useful option -a allows to recursively copy directories by preserving inode information (syncing dirs). Example: rsync -av user@remote_host:remote_dir local_dir | |
| scp [-pr] source destination | |
| Secure remote file copy. With -p preserve owner, group and time stamps in the copied file[s]. The arguments are of the form [[user@]host:]filename. | |
| stat [-f] [-Z] file[s] | |
| Display attributes of files, with option -f of file systems. Prints with -Z also security context information if available. | Documentation |
| touch [-r ref_file] [-t [[CC]YY]MMDDhhmm[.ss]] file[s] | |
| Change file access and modification times. Used to create empty files. Timestamps can be set (-t) or copied from ref_file (-r). | Documentation |
| umask [mask] | S |
| Get or set file-creation mode mask. The files get created with permissions 0777 - mask (dirs and executables) or 0666 - mask for other files (usually mask = 022 ). See chmod for the meaning of the mode bits in mask. |