Awk by Example--转载

原文地址：

http://www.funtoo.org/Awk_by_Example,_Part_1?ref=dzone

http://www.funtoo.org/Awk_by_Example,_Part_2

http://www.funtoo.org/Awk_by_Example,_Part_3

halt7 
operator11 
root0 
shutdown6 
sync5 
bin1 
....etc. 

username: halt     uid:7 
username: operator uid:11 
username: root     uid:0 
username: shutdown uid:6 
username: sync     uid:5 
username: bin      uid:1 
....etc. 

BEGIN { 
        FS=":" 
} 
{ print $1 } 

#!/usr/bin/awk -f
BEGIN {
    FS=":"
}
{ print $1 }

/foo/ { print }

/[0-9]+.[0-9]*/ { print }

$1 == "fred" { print $3 }

$5 ~ /root/ { print $3 }

{ 
    if ( $5 ~ /root/ ) { 
        print $3 
    }
}

{
    if ( $1 == "foo" ) {
        if ( $2 == "foo" ) {
            print "uno"
        } else {
            print "one"
        }
    } else if ($1 == "bar" ) {
        print "two"
    } else {
        print "three"
    }
}

! /matchme/ { print $1 $3 $4 }

{
    if ( $0?!~ /matchme/ ) {
        print $1 $3 $4
    }
}

( $1 == "foo" ) && ( $2 == "bar" ) { print } 

BEGIN { x=0 } 
/^$/  { x=x+1 } 
END   { print "I found " x " blank lines.?:)" } 

x="1.01" 
# We just set x to contain the *string* "1.01" 
x=x+1 
# We just added one to a *string* 
print x 
# Incidentally,these are comments?:) 

2.01

{ print ($1^2)+1 }

FS="t+"

FS="[[:space:]]+"

FS="foo[0-9][0-9][0-9]"

NF == 3 { print "this particular record has three fields: " $0 }

{
    if ( NF > 2 ) {
        print $1 " " $2 ":" $3 
    }
}

(NR < 10 ) || (NR > 100) { print "We are on record number 1-9 or 101+" }

{
    #skip header
    if ( NR > 10 ) {
        print "ok,now for the real information!"
    }
}

Jimmy the Weasel
100 Pleasant Drive
San Francisco,CA 12345
Big Tony

200 Incognito Ave.

Suburbia,WA 67890

BEGIN {
    FS="n"
    RS=""
}

BEGIN {
    FS="n"
    RS=""
}
{ print $1 "," $2 "," $3 }

Jimmy the Weasel,100 Pleasant Drive,San Francisco,CA 12345
Big Tony,200 Incognito Ave.,Suburbia,WA 67890

print "Hello","there","Jim!"

Hello there Jim!

BEGIN {
    FS="n"
    RS=""
    OFS=","
}
{ print $1,$2,$3 }

Cousin Vinnie
Vinnie's Auto Shop
300 City Alley
Sosueme,OR 76543

BEGIN { 
    FS="n" 
    RS="" 
    ORS="" 
} 
{

x=1

while ( x<NF ) {

print $x "t"

x++

}

print $NF "n"

} 

Jimmy the Weasel        100 Pleasant Drive      San Francisco,CA 12345 
Big Tony        200 Incognito Ave.      Suburbia,WA 67890
Cousin Vinnie   Vinnie's Auto Shop      300 City Alley  Sosueme,OR 76543

{
    count=1
    do {
        print "I get printed at least once no matter what" 
    } while ( count?!= 1 )
}

for ( initial assignment; comparison; increment ) {
    code block
}

for ( x = 1; x <= 4; x++ ) {
    print "iteration",x
}

iteration 1
iteration 2
iteration 3
iteration 4

while (1) {
    print "forever and ever..."
}

x=1
while(1) {
    print "iteration",x
    if ( x == 10 ) {
        break
    }
    x++
}

x=1
while (1) {
    if ( x == 4 ) {
        x++
        continue
    }
    print "iteration",x
    if ( x > 20 ) {
        break
    }
    x++
}

for ( x=1; x<=21; x++ ) {
    if ( x == 4 ) {
        continue
    }
    print "iteration",x
}

myarray[1]="jim"
myarray[2]=456

for ( x in myarray ) {
    print myarray[x]
}

jim
456

456
jim

a="1"
b="2"
c=a+b+3

myarr["1"]="Mr. Whipple"
print myarr["1"]

myarr["1"]="Mr. Whipple"
print myarr[1]

myarr["name"]="Mr. Whipple"
print myarr["name"]

delete fooarray[1]

if ( 1 in fooarray ) {
    print "Ayep!  It's there."
} else {
    print "Nope!  Can't find it."
}

#!/usr/bin/awk -f
BEGIN {
    x=1
    b="foo"
    printf("%s got a?%d on the last testn","Jim",83)
    myout=sprintf("%s-%d",b,x)
    print myout
}

Jim got a 83 on the last test
foo-1

mystring="How are you doing today?"
print mystring[3]

awk: string.gawk:59: fatal: attempt to use scalar as array

print length(mystring)

24

print index(mystring,"you")

9

print tolower(mystring)
print toupper(mystring)
print mystring

how are you doing today?
HOW ARE YOU DOING TODAY?
How are you doing today?

mysub=substr(mystring,startpos,maxlen)

print substr(mystring,9,3)

you

print match(mystring,/you/),RSTART,RLENGTH

9 9 3

sub(regexp,replstring,mystring)

sub(/o/,"O",mystring)
print mystring
mystring="How are you doing today?"
gsub(/o/,mystring)
print mystring

HOw are you doing today?
HOw are yOu dOing tOday?

numelements=split("Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec",mymonths,",")

print mymonths[1],mymonths[numelements]

Jan Dec

{
    print length() 
}

23 Aug 2000    food    -    -    Y    Jimmy's Buffet    30.25

23 Aug 2000    -    inco    -    Y    Boss Man        2001.00

#!/usr/bin/awk -f
BEGIN {
    FS="t+"
    months="Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec"
}
function monthdigit(mymonth) {

return (index(months,mymonth)+3)/4

}

print monthdigit("Mar")

3

        
function doincome(mybalance) {
    mybalance[curmonth,$3] += amount
    mybalance[0,$3] += amount        
}
function doexpense(mybalance) {

mybalance[curmonth,$2] -= amount

mybalance[0,$2] -= amount

}
function dotransfer(mybalance) {

mybalance[0,$2] -= amount

mybalance[curmonth,$3] += amount

mybalance[curmonth,$3] += amount

}

{
    curmonth=monthdigit(substr($1,4,3))
    amount=$7
#record all the categories encountered
if ( $2?!= "-" )
    globcat[$2]="yes"
if ( $3?!= "-" )
    globcat[$3]="yes"

#tally up the transaction properly
if ( $2 == "-" ) {
    if ( $3 == "-" ) {
        print "Error: inc and exp fields are both blank!"
        exit 1
    } else {
        #this is income
        doincome(balance)
        if ( $5 == "Y" )
            doincome(balance2)
    }
} else if ( $3 == "-" ) {
    #this is an expense 
    doexpense(balance)
    if ( $5 == "Y" ) 
        doexpense(balance2)
} else {
    #this is a transfer
    dotransfer(balance)
    if ( $5 == "Y" ) 
        dotransfer(balance2)
}                        
}

END {
    bal=0
    bal2=0        
    for (x in globcat) {
        bal=bal+balance[0,x]
        bal2=bal2+balance2[0,x]    
    }
    printf("Your available funds:?%10.2fn",bal)
    printf("Your account balance:?%10.2fn",bal2)        
}

Your available funds:    1174.22
Your account balance:    2399.33

,put all the above code into a text file called??and do?,and then type?. The balance script will then add up all your transactions and print out a two-line balance summary for you.