awk Utility 20 Example

1. function is to print all input lines
awk ' {print $} ' F Ilename
2. Print the input file line eighth
awk ' Nr==8{print $} ' F Ilename
3. Use awk to print the first field of all rows of a file
Awk-f: ' {print $} ' F Ilename
4. Print the total number of input lines
awk ' begin{num=0;} {num++;} End{print num} ' f ilename
awk ' End{print NR} ' F Ilename
5. Print the number of fields per row
Awk-f: ' {print nf,$0} ' F ilename
6. Print the value of the last field in the last line
Awk-f: ' End{print $NF} ' filename
7. The number of printed fields is greater than or equal to 4 rows
Awk-f: ' Nf>=4{print $} ' F Ilename
8. Print the total number of all fields in a file
Awk-f: ' Begin{count=0}{count=count+nf:}{print count} ' F Ilename
9. Print user name with UID within 30-40 range
Awk-f: ' $>=30&&s3<=40{print $ ' F ilename
10. Flashback all fields of the file
Awk-f: ' {for (i=nf;i>0:i--)} {if (i!=1} {printf "%s:", $i};} else{printf ("%s\n", $i);}
#!/bin/awk-f
begin{
F= ":"
}
{
for (i=nf;i>0;i--)
{
if (i!=1)
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printf ("%s:", $i)
｝
Else
{
printf ("%s\n", $i)
}
}
}
11. Print 5 to 26 lines
Awk-f: ' Nr>=5&&nr<=26{print} ' F ilename12. Add the title "document" to the top of the file
Awk ' Bengin{print ' Document}{print} ' f Ilename
13. Interlaced removal
Awk ' {if (nr%2==1) {print}} ' F Ilename
14. Total number of rows with more than 5 printed fields
Awk-f: ' Begin{num=0;} {if (nf>=5) {num++;}} END {print num;} ' f Ilename
15. Write an awk script to count the various types of files in/dev
#!/bin/awk-f
begin{
Ff=0
Dd=0
Bb=0
Cc=0
Pp=0
Ss=0
Ll=0
}
{
if ($ ~/^-/)
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ff++
｝
if ($ ~/^p/)
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pp++
｝
if ($ ~/^b/)
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bb++
｝
if ($ ~/^/)
｛
Cc++
｝
if ($ ~/^d/)
｛
dd++
｝
if ($ ~/^l/)
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ll++
｝
if ($ ~/^s/)
{s++
｝
}
end{
Print "f ile:", F F
Print "directory:", DD
Print "Character:", CC
Print "Block:", BB
Print "Link:", ll
Print "Sockt:", SS
print "Pipe:", pp
}
16. Write an awk script that reads IP from a file and tests the IP address
#!/bin/awk-f
{
if (System ("Ping-c 1" >/dev/null) ==0)
{
Print $ YES
}
Else
{
Print $ NO
}
}
17. Write an awk script to read the file to add the user
#!/bin/awk-f
{
If (System ("Useradd" 2>/dev/null) ==0)
{
Print "User:" $ "Add"
}
Else
{
Print "User" $ "error"
}
}
18. Write an awk script that filters out legitimate IP addresses
#!/bin/awk-f
begin{
Fs= ":"
}
{
if (1>0&&$1<255&&$2>=0&&$2<=255$3>=0&&$3<=255$4>=0& &$4<=255{
Print $
}
}
19. Write an awk script that extracts the first word per line
#!/bin/awk-f
begin{
Fs= "[^a-z]+"
}
{f irst=0
F lag=0
for (i=1;i<=nf;i++)
{
If ($I!) =null}
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if (f lag==0)
{
F irst=i
F lag=1
}
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}
Print $f Irst
}
20. Write an awk script that prints the first and last words of each line
#!/bin/awk-f
begin{
Fs= "[^a-z]+"
}
{f irst=0
F lag=0
Last=0
for (i=1;i<=nf;i++)
{
If ($I!) =null}
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Last=i
if (f lag==0)
{
F irst=i
F lag=1
}｝
}
Print $f irst "" $last
}

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awk Utility 20 Example