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reading line by line a variable

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# 1  
Old 07-02-2008
Bug reading line by line a variable
Hello,

I have a variable Diskfree and I would like to read it line by line to extract information, I don't know how to get the line

Code:
Diskfree=`df -h | grep dev`

I want to make a loop to get each value of this line, but I don't know how to get the line. I've seen sample with standard input but not a variable

Code:
while "something read line of Diskfree?"
do
dev=`echo $line | awk '{print $1}'`
size=`echo $line | awk '{print $2}'`
...
done

Smilie
# 2  
Old 07-02-2008
Code:
Diskfree=`df -h | grep dev`
for line in $Diskfree
do
  dev=`echo $line | awk '{print $1}'`
  size=`echo $line | awk '{print $2}'`
  ...
done

# 3  
Old 07-02-2008
Code:
 df -h | awk '/dev/ { printf "%s %s\n", $1,$2}'

# 4  
Old 07-02-2008
It doesn't seem to work.

I'd like that $line contain really the line and not one part off the line : one word.
I have several HD to check.
# 5  
Old 07-02-2008
Without variable:

Code:
c=0; df -tfuseblk|while IFS= read -r;do 
  printf "line %d is -->%s<--\n" $((++c)) "$REPLY" 
done

output:

Code:
% c=0; df -tfuseblk|while IFS= read -r;do
  printf "line %d is -->%s<--\n" $((++c)) "$REPLY"
done
line 1 is -->Filesystem           1K-blocks      Used Available Use% Mounted on<--
line 2 is -->/dev/sdb2             60926512  52040560   8885952  86% /media/USB_002<--
line 3 is -->/dev/sdb3             64484908  22401208  42083700  35% /media/USB_003<--
line 4 is -->/dev/sdb1             30876896   6648776  24228120  22% /media/USB_001<-

With variable and here string (ksh93, bash, zsh):

Code:
d=$(df -tfuseblk) c=0
while IFS= read -r; do
  printf "line %d is -->%s<--\n" $((++c)) "$REPLY"
done<<<"$d"

output:

Code:
% d=$(df -tfuseblk) c=0
% while IFS= read -r; do
while>   printf "line %d is -->%s<--\n" $((++c)) "$REPLY"
while> done<<<"$d"
line 1 is -->Filesystem           1K-blocks      Used Available Use% Mounted on<--
line 2 is -->/dev/sdb2             60926512  52040560   8885952  86% /media/USB_002<--
line 3 is -->/dev/sdb3             64484908  22401208  42083700  35% /media/USB_003<--
line 4 is -->/dev/sdb1             30876896   6648776  24228120  22% /media/USB_001<--

With process substitution (ksh93, bash, zsh):

Code:
c=0; while IFS= read -r; do
  printf "line %d is -->%s<--\n" $((++c)) "$REPLY"
done< <(df -tfuseblk)

output:

Code:
% c=0; while IFS= read -r; do
while>   printf "line %d is -->%s<--\n" $((++c)) "$REPLY"
while> done< <(df -tfuseblk)
line 1 is -->Filesystem           1K-blocks      Used Available Use% Mounted on<--
line 2 is -->/dev/sdb2             60926512  52040560   8885952  86% /media/USB_002<--
line 3 is -->/dev/sdb3             64484908  22401208  42083700  35% /media/USB_003<--
line 4 is -->/dev/sdb1             30876896   6648776  24228120  22% /media/USB_001<--

And given your original post, it seams you need something like this:

Code:
{ read 
  while read fs blks used free usepct mnt; do
    printf "dev: %s, size: %d\n" "$fs" "$blks"
  done 
} < <(df -tfuseblk)

output:

Code:
% { read; while read fs blks used free usepct mnt; do
  printf "dev: %s, size: %d\n" "$fs" "$blks"
done;}< <(df -tfuseblk)
dev: /dev/sdb2, size: 60926512
dev: /dev/sdb3, size: 64484908
dev: /dev/sdb1, size: 30876896

Last edited by radoulov; 07-02-2008 at 12:07 PM..
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