commands to display file contents cat pr more less 1. cat - conCATonate or display entire file contents cat /etc/passwd 2. pr - format files with headings including the filename and page numbers pr /etc/motd | lpr (formats the message-of-the-day file and directs the output to the default printer) 3. more - display file contents one page at a time cat /etc/passwd | more is the same as: more /etc/passwd 4. less - display file contents one page at a time ls | less keys used with the more and less commands: up arrow key = up 1 line down arrow key = down 1 line spacebar = down 1 screen b = back up 1 screen q = quit h = display help screen commands to display file & directory attributes ls pwd du find tree whereis On a Linux file server used by several clients, there is a frequent need to find files, modify files, share files and examine statistics about files. Linux has a number of very useful commands for doing these kinds of tasks 1. ls - list directory contents ls (ls with no options: list files in current directory) ls -a (list hidden files - files that begin with "." character) ls -l (long/detailed listing) ls -l /etc (list files in a specific directory) 1 ls color (list files with colored highlighting) color codes for files: grey = regular file dark blue = directory light blue = symbolic link green = executable yellow = socket brown = FIFO commands to delete, copy, move & rename files & directories cp mv rm mkdir rmdi r cpio On a Linux file server used by several clients, there is a frequent need to find files, modify files, share files and examine statistics about files. Linux has a number of very useful commands for doing these kinds of tasks 1. cp - copy file cp passwd passwd_new 2. mv - move file mv filename newfilename 3. rm - remove file rm filename 4. mkdir - make directory cd abc ; mkdir dir1 dir1/subdir 5. rmdir - remove empty directory rmdir -p dir1/subdir (the -p option causes the removal of all parent directories, not just the subdirectories, in the specified path) 6. cpio - copy directory structures from one directory to another, one file system to another. cpio - copy files (usually used with the "find" command). Example of copying all the files from one directory to another: 2 cd /olddirectory (go to the directory that you want to copy) find . -depth -print | cpio -padm /newdirectory Note: doing this procedure from the root "/" directory will usually cause problems - you will probably run out of space on the new directory since the "find" command will probably end up copying the entire contents of several file systems into your new directory, which will not fit of course. You WILL have problems copying files from actively used file systems, especially if you are copying the entire root file system or a database, etc. The only safe way to copy files that may be in use is to insure that they are NOT in use. You do this by running shutdown without the "-h" option. This will put the system into single user mode. Then you can safely copy files that might normally be in use by the OS or by some user application, like a DBMS app (Oracle, MYSQL, and such). Normally, you would do this after hours when it would not be an inconvenience for your users. commands to search file contents grep cmp comm diff file uniq wc 1. grep - get regular expression in other words, search for strings of characters: grep "/bin/sh" /etc/passwd (search for "/bin/sh" in the password file) grep -i root /etc/passwd (ignore upper/lower case) 2. cmp - conCATonate or display entire file contents. cmp /etc/passwd 3. comm - display duplicate or unique lines between two sorted files in 3 column format. comm /etc/passwd /etc/passwd.old 4. diff - display the lines that differ between two files. differing lins are displayed on alternate lines with a "<" character prepended to lines from file1 and a ">" character prepended to lines from file2. diff /etc/passwd /etc/passwd.old 5. file - display the type of the file (ascii text, directory, c program, empty, executable etc.) file unknownfile file * | grep directory 3 6. uniq - display duplicate or unique lines within a single sorted file. uniq myfile.txt 7. wc - display the number of words, lines and characters in a file wc myfile.html 8. SEE ALSO: zgrep, zcomp, & zdiff 4 . find tree whereis On a Linux file server used by several clients, there is a frequent need to find files, modify files, share files and examine statistics about files. Linux has a number of very. mkdir rmdi r cpio On a Linux file server used by several clients, there is a frequent need to find files, modify files, share files and examine statistics about files. Linux has a number of very