Well, it depends. The following syntax affects the IFS only for the read command inside the while loop, so you don't need to worry/restore the previous value of IFS for the statements after the loop.
I understand that, but that is only in the case of
what I am saying is I have been told to do it differently in the format of:
I am unsure why exactly I must use OLDIFS, but I assume it's a problem with sh? so far all tests I have done using IFS in while loop in sh, ash, bash, ksh all seem to work fine... So I really have no idea why my tutor seems to think otherwise, would have been helpful if I asked him to expand on this..
Quote:
Originally Posted by radoulov
Sometimes it's convenient to force a sub-shell execution to avoid affecting the current shell environment, but it depends on what exactly you' re trying to achieve.
I think the basic logic behind it is, 'sh' doesn't handle subshells very well, while bash/ksh etc do handle subshells fine. But the tutor is trying to teach us portable languages.
Quote:
Originally Posted by radoulov
Please post the exact command(s)/output (just copy/paste) you' re getting.
Like I have already mentioned my problems using OLDIFS variable is that my constant variables that i use to echo statements to standard output are missing the n's
however this is NOT for all my variables I have just checked over and tested a few of them, and they work, however addding, and failure to delete is leaving out n's, which seems wierd to me. You would think they all would not work, or they all would work. Not randomly willy nilly.
As you can see from my first post, I showed the while loop calling functions, so in the case of using OLDIFS/NEWIFS I assume those functions and variables called from there also use it. which is why i'm missing some "n's"
DATAEMPTY seems to work, as does USAGE...
RECADDED does not
thanks for the help, if you need to see more of my code, eg where I am calling the variables from just ask
Hi all,
Ok os heres my situation. I have created a database style program that stores a persons info (name,address,phone number etc.) in a file ("database"). after i read in all the values above, i assign them to a line variable:
line="$name^$address^$phonenum" >> phonebuk
as you can see... (1 Reply)
Hi!
I am working in korn shell. I want to reset the dimiliter for the set command to "|" but instead of a command prompt return I am getting something as below
After issuing the command I am getting this....as if the shell is expecting something else. Can anybody suggest what's the problem.
... (2 Replies)
Hi,
This is out of curiosity:
I wanted to extract year, month and date from a variable, and thought that combining read and IFS would help, but this doesn't work:
echo "2010 10 12" | read y m d
I could extract the parts of the date when separated by a -, and setting IFS in a subshell:
... (3 Replies)
Given the scenario like this, if at all if have to use IFS on the below given example, how it should be used.
IFS=/
eg:
/xyz/123/348/file1
I want to use the last slash /file1 . So can anyone, suggest me how to pick the last "/" as a IFS. (4 Replies)
Hi,
while ; do
echo "Please enter "
read enter
yyyy=${enter:0:4}
mm=${enter:5:2}
dd=${enter:8:2}
result=`validateDate $yyyy $mm $dd`
When does the loop keeping repeating till?? till 1 is equal to 1?
what does this mean "${enter:0:4}" .The 0 and 4 part??
... (3 Replies)
hi I keep getting an error with this nested if statement and am getting the error unexpected end of file, can anyone help me as to why this wont execute?
#!/bin/bash
#script to check wether the -i -v statements run correctly
removeFile ()
{
mv $1 $HOME/deleted
}... (3 Replies)
I am using bash and resetting IFS as below when reading the command line arguments. I do this so I can call my script as in Ex1.
Ex1: ./synt2d-ray3dmod.bash --xsrc=12/20/30
This allows me to split both sides so that when I do "shift"
I can get 12/20/30
What I do not understand is... (21 Replies)
Hi ,
i am in my initial learning phase of unix. i was going thru the function part.
below is the example which was there but i am not able to understand logic and the use of IFS(internal field separator)
lspath() {
OLDIFS="$IFS"
IFS=:
for DIR in $PATH ; do echo $DIR ; done
IFS="$OLDIFS"... (8 Replies)