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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`

echo $j


result after run:


Here is my data:

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

echo "$j"

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And put care about single quotes on IFS because IFS=$"\n" will split also "nn" strings. I found set IFS more reliable than use more complicated syntax or functions. – erm3nda Aug 25 '15 at 4:08
apparently it is advised to unset IFS afterwards, so that other commands are not influenced in this same shell. – Boris Däppen Oct 8 '15 at 14:49

for loops split on any whitespace (space, tab, newline) by default; the easiest way to work on one line at a time is to use a while read loop instead, which splits on newlines:

while read i; do echo "$i"; done < ./file_wget_med

I would expect your command to spit out one word per line (that's what happened when I tested it out with a file of my own). If something else is happening, I'm not sure what could be causing it.

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This is also a good alternative to for i in `ls`; do echo $1; done, by piping the output to the while command: ls|while read i; do echo $i; done. This works on file/folder names with spaces, without needing to change environment variables. Very good answer. – jishi Jun 1 '15 at 21:23
the while didn't handle the first and last lines very, not as well as the for loop with IFS – Grant Bowman Jul 28 '15 at 15:16
@jishi Since it's primarily designed for display, and is responsive to terminal-window size and such, ls is not considered safe for use with | (the pipe operator). find is more flexible in addition to being safer for this purpose. – SeldomNeedy Nov 20 '15 at 21:48
@GrantBowman Depending on how the file is delimited, it might work better if you try while read -r i instead of just while read i. – SeldomNeedy Nov 20 '15 at 21:56
This is a GREAT answer, I used it to turn a list I had into PLIST entries for an IOS app I was developing on mac OSX. I replaced the file input by piping the clipboad using pbpaste -> pbpaste | while read t; do echo "<string>$t</string>"; done – Big Rich Mar 8 at 15:43

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