Ubuntu – How to read complete line in ‘for’ loop with spaces

bashcommand linescripts

I am trying to run a for loop for file and I want to display whole line.
But instead its displaying last word only. I want the complete line.

for j in `cat ./file_wget_med`

do
echo $j

done

result after run:

Found.

Here is my data:

$ cat file_wget_med
2013-09-11 14:27:03 ERROR 404: Not Found.

Best Answer

for loop splits when it sees any whitespace like space, tab, or newline. So, you should use IFS (Internal Field Separator):

IFS=$'\n'       # make newlines the only separator
for j in $(cat ./file_wget_med)    
do
    echo "$j"
done
# Note: IFS needs to be reset to default!

Explanation:

The sleep command make delay for a specified amount of time (in seconds). With sleep 1 delay would be for 1 second. You can change for more time delay by incrementing the second parameter or for delaying less than 1 second divide it to low units; Like sleep .1 for 1/10 second delay or sleep .001 for 1/1000 second delay and etc.

The clear command clear the terminal screen.

Even better you can do this through below `awk` command:

awk '{i=1; while(i<=NF){ print $((i++)); system("sleep 1; clear") }}' read

Explanation:

In awk, the NF specifies the total number of fields in the current input record/line, so by using a variable as a counter (i) and looping over it, we are printing all of them from 1st position to the end of them (NF). Then by using the system("sleep 1; clear") part, we are telling to awk to calling the system commands to sleeping for 1 second and clearing the screen.

In above we are displaying the input file as word by word. If you are going to display it line by line add IFS=$'\n' in the script like:

IFS=$'\n'
for word in $(< read)
do
    echo "$word"
    sleep 1
    clear
done

And change the awk command like:

awk '{ $0; system("sleep 1; clear") }1' read

$0 specifies the current line. and the 1 on end enables the default awk's print command.

Ubuntu – Problem with spaces in file names

The multiple quote from the echo ' is complicating the thing.

You can just use:

for f in *; do stat -- "$f"; done

But also

stat -- *

...and if you want to collect the files and then apply the command (why?) you can go with (but be careful with file containing new lines...(1))

for f in *; do echo "$f"; done | xargs stat --

...and if you want hidden files too, just use * .* as a pattern, but then remember that . and .. will be in the set.

As an aside, you shouldn't parse ls output.

(1) but if you have file names with newlines, you somewhat deserve it... ;-)

Best Answer

Related Solutions

Command-Line – Print One Line at a Time from Text File

Explanation:

Even better you can do this through below awk command:

Explanation:

Ubuntu – Problem with spaces in file names

Related Question

Even better you can do this through below `awk` command: