Awk limitation


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Awk limitation
# 29  
Old 09-30-2007
Don't just rely on other people. Read the man page for cut. Then construct a cut command that uses ":" as a delimiter, and prints field 1.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. AIX

What is the limitation in AIX?

Hi All, i got few questions... 1) What is the maximum number of files that we can save under a single directory in AIX ? (* we have enough storage/disk space) 2) And what is the maximum number of sub - directories in side a directory? I know that...every directory is a (special)... (11 Replies)
Discussion started by: System Admin 77
11 Replies

2. UNIX for Dummies Questions & Answers

Limitation in addition

whats wrong with this addition? Whats the maximum number of digits can be handled? pandeeswaran@ubuntu:~/Downloads$ const=201234454654768979799999 pandeeswaran@ubuntu:~/Downloads$ let new+=const pandeeswaran@ubuntu:~/Downloads$ echo $new -2152890657037557890 pandeeswaran@ubuntu:~/Downloads$ (4 Replies)
Discussion started by: pandeesh
4 Replies

3. Shell Programming and Scripting

Limitation on rm command

Hi all, does any one know ,if there is any limitation on rm command limitation referes here as a size . Ex:when my script try to rum rm command which have size of nearly 20-22 GB ..CPU load gets high ? if anyone know the relation of CPU load and limitation of rm command . (8 Replies)
Discussion started by: niteshagrawal06
8 Replies

4. UNIX for Advanced & Expert Users

size for sum variable limitation on awk

Hello first, truth been told, I'm not even close to be advanced user. I'm posting here because maybe my question is complicated enough to need your expert help I need to use awk (or nawk - I don't have gawk) to validate some files by computing the total sum for a large numeric variable. It... (1 Reply)
Discussion started by: cwitarsa
1 Replies

5. HP-UX

Limitation on *.ext

Is there a size limit when passing an argument using wildcards? I.E. when I pass an argument in the form (like) "ftp_auto *.txt" - is there a limitation on the size of UNIX expanding "*.txt" ? (1 Reply)
Discussion started by: vslewis
1 Replies

6. UNIX for Dummies Questions & Answers

grep limitation

Hello, I am looking for a way to get around an issue, as I am using the grep command in a very common situation: grep ^50 File.*.txt | "some awk process" My problem is that bash throws me an error on the grep command if the directory in question contains several thousands files. ... (6 Replies)
Discussion started by: Indalecio
6 Replies

7. Shell Programming and Scripting

Is this a bug or a limitation?

Hi, I'm having a problem with a while loop syntax that doesn't seem to loop correctly. TODAY=`date +%d%m%Y` while read hostname #for hostname in $(cat $CONFIG) do OUTFILE=/tmp/health_check.$hostname.$TODAY if then touch $OUTFILE func_header else rm $OUTFILE ... (2 Replies)
Discussion started by: gilberteu
2 Replies

8. Shell Programming and Scripting

Limitation of ls command

Hi, Iam using an alias to get the file count from one directory using normal ls command like ls file*|wc -l.If my file increases more than 35,000 ,my alias is not working.It shows that arg list too long. is that can be limitation of ls or problem in alias? I would appreciate if anyone can... (2 Replies)
Discussion started by: cskumar
2 Replies

9. HP-UX

HP-UX 11i - File Size Limitation And Number Of Folders Limitation

Hi All, Can anyone please clarify me the following questions: 1. Is there any file size limitation in HP-UX 11i, that I can able to create upto certain size of file (say 2 GB) and not more then that???? 2. At max. how many files we can able to keep inside a folder???? 3. How many... (2 Replies)
Discussion started by: sundeep_mohanty
2 Replies

10. Shell Programming and Scripting

find limitation

Hi , i'm trying to use "find "command with "-size "option but i encounter 2gb file limitation. Can you confirm this limitation ? Is there a simple way to do the same thing ? My command is : <clazz01g-notes01>/base/base01 # find /base/base01 -name '*.nsf' -size +5242880000c -exec ls... (2 Replies)
Discussion started by: Nicol
2 Replies
Login or Register to Ask a Question
A2P(1)							 Perl Programmers Reference Guide						    A2P(1)

NAME
a2p - Awk to Perl translator SYNOPSIS
a2p [options] filename DESCRIPTION
A2p takes an awk script specified on the command line (or from standard input) and produces a comparable perl script on the standard out- put. Options Options include: -D<number> sets debugging flags. -F<character> tells a2p that this awk script is always invoked with this -F switch. -n<fieldlist> specifies the names of the input fields if input does not have to be split into an array. If you were translating an awk script that processes the password file, you might say: a2p -7 -nlogin.password.uid.gid.gcos.shell.home Any delimiter can be used to separate the field names. -<number> causes a2p to assume that input will always have that many fields. -o tells a2p to use old awk behavior. The only current differences are: o Old awk always has a line loop, even if there are no line actions, whereas new awk does not. o In old awk, sprintf is extremely greedy about its arguments. For example, given the statement print sprintf(some_args), extra_args; old awk considers extra_args to be arguments to "sprintf"; new awk considers them arguments to "print". "Considerations" A2p cannot do as good a job translating as a human would, but it usually does pretty well. There are some areas where you may want to examine the perl script produced and tweak it some. Here are some of them, in no particular order. There is an awk idiom of putting int() around a string expression to force numeric interpretation, even though the argument is always inte- ger anyway. This is generally unneeded in perl, but a2p can't tell if the argument is always going to be integer, so it leaves it in. You may wish to remove it. Perl differentiates numeric comparison from string comparison. Awk has one operator for both that decides at run time which comparison to do. A2p does not try to do a complete job of awk emulation at this point. Instead it guesses which one you want. It's almost always right, but it can be spoofed. All such guesses are marked with the comment ""#???"". You should go through and check them. You might want to run at least once with the -w switch to perl, which will warn you if you use == where you should have used eq. Perl does not attempt to emulate the behavior of awk in which nonexistent array elements spring into existence simply by being referenced. If somehow you are relying on this mechanism to create null entries for a subsequent for...in, they won't be there in perl. If a2p makes a split line that assigns to a list of variables that looks like (Fld1, Fld2, Fld3...) you may want to rerun a2p using the -n option mentioned above. This will let you name the fields throughout the script. If it splits to an array instead, the script is probably referring to the number of fields somewhere. The exit statement in awk doesn't necessarily exit; it goes to the END block if there is one. Awk scripts that do contortions within the END block to bypass the block under such circumstances can be simplified by removing the conditional in the END block and just exiting directly from the perl script. Perl has two kinds of array, numerically-indexed and associative. Perl associative arrays are called "hashes". Awk arrays are usually translated to hashes, but if you happen to know that the index is always going to be numeric you could change the {...} to [...]. Itera- tion over a hash is done using the keys() function, but iteration over an array is NOT. You might need to modify any loop that iterates over such an array. Awk starts by assuming OFMT has the value %.6g. Perl starts by assuming its equivalent, $#, to have the value %.20g. You'll want to set $# explicitly if you use the default value of OFMT. Near the top of the line loop will be the split operation that is implicit in the awk script. There are times when you can move this down past some conditionals that test the entire record so that the split is not done as often. For aesthetic reasons you may wish to change the array base $[ from 1 back to perl's default of 0, but remember to change all array sub- scripts AND all substr() and index() operations to match. Cute comments that say "# Here is a workaround because awk is dumb" are passed through unmodified. Awk scripts are often embedded in a shell script that pipes stuff into and out of awk. Often the shell script wrapper can be incorporated into the perl script, since perl can start up pipes into and out of itself, and can do other things that awk can't do by itself. Scripts that refer to the special variables RSTART and RLENGTH can often be simplified by referring to the variables $`, $& and $', as long as they are within the scope of the pattern match that sets them. The produced perl script may have subroutines defined to deal with awk's semantics regarding getline and print. Since a2p usually picks correctness over efficiency. it is almost always possible to rewrite such code to be more efficient by discarding the semantic sugar. For efficiency, you may wish to remove the keyword from any return statement that is the last statement executed in a subroutine. A2p catches the most common case, but doesn't analyze embedded blocks for subtler cases. ARGV[0] translates to $ARGV0, but ARGV[n] translates to $ARGV[$n]. A loop that tries to iterate over ARGV[0] won't find it. ENVIRONMENT
A2p uses no environment variables. AUTHOR
Larry Wall <larry@wall.org> FILES
SEE ALSO
perl The perl compiler/interpreter s2p sed to perl translator DIAGNOSTICS
BUGS
It would be possible to emulate awk's behavior in selecting string versus numeric operations at run time by inspection of the operands, but it would be gross and inefficient. Besides, a2p almost always guesses right. Storage for the awk syntax tree is currently static, and can run out. perl v5.8.0 2002-06-01 A2P(1)