[bug-gawk] Potential errors in Manual 4.1

[bamber ward]

gawk manual Edition 4.1 April 2014

 

Section 4.9.1

The program there seems to give the wrong result.

cat getline1.txt

mon/*comment*/key

rab/*commen

t*/bit

horse /*comment*/more text

 

The output is :

money

rabbit

horse ore text

 

I think what may be happening is that the _expression_:

u=index(substr($0,t+2),"*/")

counts the beginning character twice. Changing t+2 to t+3 seems to fix it, at least for

the input I have tested it on

 

typo page 120

'$1 ~/foo/ {print $2}' mail-list

/foo/ should be /li/

 

typo 7.4.9

In gawk, execution of nextfile causes additional things to happen: any ENDFILE rules

are executed except in the case as mentioned below( 'below' should be 'above')

 

zerofile.awk

I have gawk 4.0.1 on ubuntu 14.04

There may be a problem with this function or perhaps I have not understood something properly.

I note that the syntax error pertains to zerofilef.awk not zerofile.awk  so perhaps

 my formulation of zerofile() is wrong. However, to avoid using ARGV[Argind] I would need to know beforehand what this represented which rather defeats the whole point of using the function

I have mentioned this before but  this was  rejected.

cat zerofilef.awk

function zerofile(ARGV[Argind], Argind )

{

   print ARGIND,Argind, ARGV[Argind]

 

}

 

 

zerofile.awk was taken from the distribution and copied into the directory

 

~/gawk/code-> gawk -f zerofile.awk -f zerofilef.awk empty.txt nonempty.txt empty2.txt

gawk: zerofilef.awk:2: function zerofile(ARGV[Argind], Argind )

gawk: zerofilef.awk:2:                       ^ syntax error

gawk: zerofilef.awk:2: error: function `zerofile': can't use special variable `ARGV' as a function parameter

~/gawk/code->

cat user_zerofile.awk

 

 

# user_zerofile.awk --- library file to process empty input files

# bit of a 'fudge'    

    

     BEGIN { Argind = 0 }

    

     ARGIND > Argind + 1 {

         zf=ARGV[Argind]  # added

         for (Argind++; Argind < ARGIND; Argind++)

             zerofile(zf, Argind) # different

               

     }

    

     ARGIND != Argind { Argind = ARGIND }

    

     END {

       

         if (ARGIND > Argind)

            zf2=ARGV[Argind] # added

             for (Argind++; Argind <= ARGIND; Argind++)

                 zerofile(zf2, Argind) # different

                 

     }

 

 

cat user_zerofilef.awk

 

function zerofile(zf, Argind )

{

   print ARGIND,Argind, ARGV[Argind]

 

} 

 

~/gawk/code-> gawk -f  user_zerofile.awk -f user_zerofilef.awk empty.txt nonempty.txt empty2.txt

2 1 empty.txt

3 3 empty2.txt

~/gawk/code->

 

 

page 307

I am doing this in 4.0.1

the lines:

 

This tells us that gawk is now ready to execute line 67, which decides whether to give

the lines the special “field skipping” treatment indicated by the -f command-line option.

(Notice that we skipped from where we were before at line 64 to here, since the condition

if (fcount == 0 && charcount == 0) was false

 

'-f' is  incorrect( there is no such command line option  for uniq.awk);it should be -1. It would have been helpful to have shown this on the given command line 

Without it, the above condition is true and next  gives;

 return (last == $0)

Incidentally, I had to do one more n than the manual stated in dgawk before m,aline, cline were

defined.

I hope you find the above helpful

Best Wishes

David