CSC 140: Introduction to IT

1
CSC 140 Introduction to IT

• Advanced File Processing

2
Sorting

• Ordering set of items by some criteria.
• Systems in which sorting is used include
• Words in a dictionary.
• Names of people in a telephone directory.
• Numbers.

3
Sorting sort

• sort -f -i -d -l -v file1 file2,
• -d Sort in dictionary order (default.)
• -f Ignore case of letters.
• -i Ignore non-printable characters.
• -n Sort in numerical order.
• -r Reverse order of sort
• -u Do not list duplicate lines in output.

4
sort Example

• cat days.txt
• Sunday
• Monday
• Tuesday
• Wednesday
• Thursday
• Friday
• Saturday
• sort days.txt
• Friday
• Monday
• Saturday
• Sunday
• Thursday
• Tuesday
• Wednesday

5
sort Example

• cat days.txt
• Sunday
• Monday
• Tuesday
• Wednesday
• Thursday
• Friday
• Saturday
• sort -r days.txt
• Wednesday
• Tuesday
• Thursday
• Sunday
• Saturday
• Monday
• Friday

6
sort Example

• cat numbers.txt
• 101
• 5571
• 58
• 2001
• 9
• sort numbers.txt
• 101
• 2001
• 5571
• 58
• 9
• sort -n numbers.txt
• 9
• 58
• 101
• 2001
• 5571

7
Searching for Files find

• find path expression
• Search for files that match expression under
  path.
• Example expressions
• -atime x Was file accessed x days ago?
• -atime x Was file accessed
• -mtime /- x Was file modified /
• -name x Does filename match x?
• -perm x Does file match permissions x?
• -size /-x Is file larger/smaller than x
  blocks?
• -type c Is file a regular file link
  directory?
• -user n Does file belong to user n?

8
Basic Find Options

• find /usr/include -name stdio.h
• /usr/include/stdio.h
• find /usr/include -name stdio.h -ls
• 12 -rw-r--r-- 1 root bin 11461 Apr
  6 2002 /usr/include/stdio.h
• find /usr/include -type l
• /usr/include/iso/assert_iso.h
• /usr/include/iso/errno_iso.h
• ...
• /usr/include/uil
• /usr/include/xil
• find /usr/include -type d
• /usr/include
• /usr/include/xfn
• ...

9
More Find Options

• find /usr/include -mtime -7
• find /usr/include -mtime 7
• /usr/include
• ...
• /usr/include/xfn/FN_bindingset.h
• find /usr/include -perm urw,grw,or
• find /usr/include -perm urw,gr,or
• /usr/include/zconf.h
• /usr/include/zlib.h
• ...
• find /usr -name '.h'
• find cannot read dir /usr/lostfound Permission
  denied
• /usr/openwin/share/include/X11/DPS/ColorSB.h
• /usr/openwin/share/include/X11/DPS/ColorSBP.h
• ...

10
Combining find Expressions

• find /usr/include -perm urw,gr,or -user
  waldenj
• find /usr/include -perm urw,gr,or -user root
• /usr/include/zconf.h
• ...
• /usr/include/xfn/FN_compound_name.h
• find /kernel -type f -user root -size 1000 -ls
• 303 696 -rwxr-xr-x 2 root sys
  701748 May 13 2003 /kernel/drv/ip
• 801 888 -rwxr-xr-x 2 root sys
  899456 May 13 2003 /kernel/drv/sparcv9/ip
• 303 696 -rwxr-xr-x 2 root sys
  701748 May 13 2003 /kernel/strmod/ip
• 801 888 -rwxr-xr-x 2 root sys
  899456 May 13 2003 /kernel/strmod/sparcv9/ip
• 384 1768 -rwxr-xr-x 1 root sys
  1794232 May 27 2003 /kernel/genunix

11
Combining find Expressions with -o

• find /usr \( -name gnome -o -name dict \) -ls
• 68869 1 drwxr-xr-x 3 root other
  512 Dec 29 2003 /usr/demo/gnome
• 3862 1 drwxr-xr-x 2 root bin
  512 Dec 29 2003 /usr/share/lib/dict
• 20512 1 drwxr-xr-x 33 root other
  1024 Dec 29 2003 /usr/share/gnome
• 71884 2 drwxr-xr-x 4 root other
  1536 Dec 29 2003 /usr/share/gnome/pixmaps/nautilu
  s/gnome
• 3844 1 lrwxrwxrwx 1 root root
  16 Dec 29 2003 /usr/dict - ./share/lib/dict
• 26756 1 drwxr-xr-x 3 root other
  512 Dec 29 2003 /usr/gnome
• 90435 2 -rw-r--r-- 1 bin bin
  1480 May 2 2003 /usr/local/share/terminfo/g/gnom
  e

12
Cutting Text cut

• cut -d char -f -s file1 file2, ...
• Print specified fields of files.
• -c1-2 Print characters 1 through 2 of each
  line.
• -d char Use specified character as field
  separator.
• (Tab is default separator.)
• -f Print field
• -f 1,2 Print field 1 and field 2
• -f 1-2 Print all fields 1 through 2
• -s Dont print lines that dont contain
  field separator.

13
Cutting with space-separated fields
who longa pts/13 Oct 3 1111
(10.20.12.102) waldenj pts/16 Oct 8
1623 (10.20.10.77) trutat1 pts/14
Oct 8 1651 (10.20.11.151) who cut
-c1-8 longa waldenj trutat1 who cut
-c1-14 longa pts waldenj pts trutat1
pts who cut -d " " -f1 longa waldenj trutat1
14
Cutting -separated fields
tail /etc/passwd cut -d -f1,6 cribbett/expor
t/home7/cribbett matracia/export/home7/matracia m
uellerm/export/home7/muellerm nadaudm/export/hom
e7/nadaudm kohuss/export/home7/kohuss cit1403/ex
port/home7/cit1403 stevenso/export/home7/stevenso
mousem/export/home7/mousem krugd/export/home1/k
rugd frankc/export/home7/frankc