Meta Characters
 Special Characters with Special Meaning
 Used to Save Time
• / \ “ ` * ; ? { } ( ) [ ] ~ ! $ < > | & #
• # Comment Line
 Turning Off Meta Characters
• Display a Line of ****
• echo ***
 Doesn’t Work!
2

Meta Characters
 Turning Off Meta Characters
•
• \
$ echo \*\*\*
***
3

Meta Characters
 Turning Off Meta Characters
•
• ‘ ‘
‘ ‘
$ echo ‘*** ’
***
4

Meta Characters
 Turning Off Meta Characters
•
• “ “
“ “
• $ \ ` remain active
$ echo “My home is $HOME”
My home is /home/rdefe
5

Meta Characters
 Turning Off Meta Characters with “ “
• $ \ ` remain active
$ echo -e “My home is $HOME\nNext Line”
My home is /home/rdefe
Next Line
$
\n New Line
\t Tab
6

Meta Characters
 Turning Off Meta Characters
•
• “ “
“ “
• $ \ ` remain active
$ echo “Today is `date`”
Today is Mon Jan 22 22:04:46 EST 1996
7

Unix Commands
 wc [-lwc] File
1
• Word Count
• -l
• -w
• -c
File
2
… File
N
Display Number of Lines
Display Number of Words
Display Number of Characters
$ wc mbox
59 279 1473 mbox
$ wc mbox ls.file
59 279 1473 mbox
1 1 12 ls.file
60 280 1485 total
8

Unix Commands
 cmp File1 File2
• Compare Two Files (binary or text)
$ cmp s1 mbox s1 mbox differ: char 1, line 1
$ cmp p1 p2
$
9

Unix Commands
 sort [-fnr] File
1
File
2
… File
N
• Sort the Contents of a File
• -f
• -n
• -r
Ignore Case
Sort Numbers Based on Value
Reverse Order
$ cat words sand box zoo xray sam jones
$ sort words box jones sam sand xray zoo
10

Unix Commands
 uniq [-d] File
1
File
2
… File
N
• Read a Sorted File Reject or Report Duplicates
• -d Display Duplicates
$ cat stuff dos mac mvs mvs unix unix windows95
$ uniq stuff dos mac mvs unix windows95
$ uniq -d stuff mvs unix
11

Unix Commands
 compress File
1
File
2
… File
N
 uncompress File
1
File
2
… File
• Used to compress Large Files
N
$ ls -s datafile
297 datafile
$ compress datafile
$ ls -s datafile* $ uncompress datafile
177 datafile.Z
$ ls -s datafile
297 datafile
12

Unix Commands
 cut -c[col number] FileName
• Cut columns and display to screen
$ cat names
Jones John
Smith Rober
Doe John
$ cut -c1-3 names
Jon
Smi
Doe
$ cut -c1-3,11-13 names
JonJoh
SmiRob
DoeJoh
13

Unix Commands
 find Location Criteria Action
• Locate Files Based on a Search Criteria
$ find /home -name mbox -print
/home/mbox
/home/rdefe/mbox
/home/ssmith/mbox
$
$ find /home -name “mbox*” -print
$
14

Unix Commands
 find Location Criteria Action
• Specify Multiple Search Locations
$ find /home /usr -name mbox -print
/home/mbox
/home/rdefe/mbox
/home/ssmith/mbox
/usr/mbox
/usr/tmp/mbox
$
15

Unix Commands
 find Location Criteria Action
• -user [login]
• -group [GroupName]
$ find /home -user rdefe -print
/home/rdefe/mbox
/home/rdefe/doc
$ $ find /home -group unix -print
/home/rdefe/mbox
/home/rdefe/doc
/home/jsmith/p1
$
16

Unix Commands
 find Location Criteria Action
• -mtime [+|-] Days
• -links [+|-] Number
$ find /home -mtime 7 -print Files modified exactly 7 days ago
$ find /home -mtime +7 -print Files modified greater than 7 days ago
$ find /home -mtime -7 -print Files modified less than
7 days ago
17

Unix Commands
 find Location Criteria Action
• -inum [InodeNumber]
• -type [f|d]
$ find /home -inum 10203 -print Find file with inode number 10203
$ find /home -type d -print Find all directories in
/home
18

Unix Commands
 find Location Criteria Action
• -print
• -exec UnixCmds
• -ok UnixCmds
Display File Location
Execute Unix Command(s)
Interactive Unix Command(s)
$ find /home -user rdefe -exec pr {} \;
$ find /home -user rdefe -ok pr {} \;
/home/rdefe/mbox?
Prompt for Each File
19

Unix Commands
 find Examples
Implied “and”
$ find /home -user rdefe -links 2 -print
$ find /home -user rdefe -o -links 2 -print
“or”
$ find /home
\( -user rdefe -o -user jdoe \) -links 2
-print
20