Review chapter 1-3  Unix/Linux Architecture  Using the Shell 1) What is the shell 2) Program & process 3) Support different shells, shortcuts, redirections, pipes, alias, wildcards (*, ?, [], [! ]), processes 4) The first touch: telnet(PuTTY), ftp, login, using commands(date, cat, passwd, man, …), logout man sort | less man –k sort info sort sort --help 5) Working with files 9 Browsing files and directories (ls, pwd, mkdir,….) 9 File attributes e.g. drwx---r-x 2 cscqxcx cscqxcx 4096 Feb 25 2008 ch08 1|------2---| 3 |---4 ---| |---5----| |- 6 -| |----- 7 ---| |- 8 -| 1. Type 2. Access modes 3. Number of links 4. Owner (chown user file) 5. Group (chgrp group file) 6. Size in Bytes 7. Modification Date and Time 8. Name 9 Special files : . and .. 9 Protecting files and directories Permissions for directories: r, w, x Permissions for files: r, w, x Applications Shell Kernel Hardwaree.g. – rwx rwx rwx – rw- r-- r-- d rw- r-x r-x Changing file attributes (chmod mode file: set up a mode; add / remove a permission to owner; group members or other users; number code of permission) e.g. chmod go=rw filename chmod g-w,o-r,a+x filename chmod 777 file1 file2 file3 9 Copy/move/remove files (cp, mv, rm, rmdir,…) 9 File archives ( tar 9 File compression Command Extension(s) uncompression zip .zip unzip compress .tar.z .taz .tz uncompress gzip .tar.gz .tgz gunzip e.g. tar cvf tarfile.tar file1, file2,… zip zipfile.zip file(s) gzip tarfile.tar compress tarfile.tar 9 Text editor vi Command mode, text mode, insert / remove word/lines, search/replace text, read another file, copy /paste blocks,…. 9 … 6) Data processing 9 Sort (sort –tc –r [+pos1 [-pos2]] {sortfield –bfMn}*) 9 Compare files(cmp, diff) 9 Scheduling (crontab –ler [username], at –csm time [date [,year]] [+increment] [script]) 9 Find utility (find pathList expression) name pattern perm oct type ch user userid group groupid atime count ctime count exec command e.g. find . -name “*.c” -exec chmod o+r ‘{}’ \; find . -exec grep “public” ‘{}’ \; -print9 Regular expression (see handouts) 9 Filter patterns (grep, egrep, fgrep) grep -hilnvw pattern {fileName}* (see Regular expression examples section & homework2 9 Pattern scanning and processing (see awk handout & homework2) awk -Fc -f awk.code InputFile awk -Fc 'condition action' InputFile e.g. awk -F: '/cscqxcx/ {print $1," uses ",$7}' /etc/passwd 9 Stream Editor (sed) e.g. sed 's/^/ /' file > file.new -indents each line in the file by 2 spaces sed 's/^ *//' file > file.new – removes all leading spaces from each line of the file sed '/a/d' file > file.new – deletes all lines containing 'a' sed -e 's/^/<< /' -e 's/$/ >>/' file Example: add two lines in the beginning of the file % cat sed1 1i\ abcd\ efg % sed -f sed1 file > file.new % cat sed2 1,3c\ Lines 1-3 are censored % cat dummy2 one two three four five six % sed -f sed2 dummy2 Lines 1-3 are censored four five six 9 Translate utility(tr –cds string1 string2) 9