I want any stdout to display on one line only. Each successive line should overwrite the last.
Typically, I would do
echo -ne "Overwrite me. \033[0K\r"
But now I want to pipe the output, and since echo is not a filter I need to use sed or something e.g.
cat story.txt | some.sed.like.util.for.replacing.$.with.\033[0K\r
sed can't be used since sed will always append a newline to it's output. You need to use a while loop in the shell:
while read -r line ; do
echo -en "\r\033[0K${line}"
sleep 1
done < story.txt
Related
I'm completely lost trying to do something which I thought would be very straightforward : read a file line by line and output everything on one line.
I'm using bash on RHEL.
Consider a simple test case with a file (test.in) with following content:
one
two
three
four
I want to have a script which reads this files and outputs:
one two three four
Done
I tried this (test.sh):
cat test.in | while read in; do
printf "%s " "$in"
done
echo "Done"
The result looks like:
# ./test.sh
foure
Done
#
It seems that the printf causes the cursor to jump to the first position on the same line immediately after the %s. The issues holds when doing echo -e "$in \c".
Any ideas?
another answer:
tr '[:space:]' ' ' < file
echo
This must be safest and most efficient as well. Use \n if you want to only convert new lines instead of any white spaces.
You can use:
echo -- $(<test.in); echo 'Done'
one two three four
Done
echo -- `cat file` | tail -c +4
the -- is to protect you from command line options. But in my shell the -- is printed out. I think that might be a bug. Will have to check.
So you need to check if you have to include | tail -c +4 in your implementation.
I have a file that looks like this:
some random
text
00ab46f891c2emore random
text
234324fc234ba253069
and yet more text
only one line in the file contains only hex characters (234324fc234ba253069), how do I extract that? I tried sed -ne 's/^\([a-f0-9]*\)$/\1/p' file I used line start and line end (^ and &) as delimiters, but I am obviously missing something...
Grep does the job,
$ grep '^[a-f0-9]\+$' file
234324fc234ba253069
Through awk,
$ awk '/^[a-f0-9]+$/{print}' file
234324fc234ba253069
Based on the search pattern given, awk and grep prints the matched line.
^ # start
[a-f0-9]\+ # hex characters without capital A-F one or more times
$ # End
sed can make it:
sed -n '/^[a-f0-9]*$/p' file
234324fc234ba253069
By the way, your command sed -ne 's/^\([a-f0-9]*\)$/\1/p' file is working to me. Note, also, that it is not necessary to use \1 to print back. It is handy in many cases, but now it is too much because you want to print the whole line. Just sed -n '/pattern/p' does the job, as I indicate above.
As there is just one match in the whole file, you may want to exit once it is found (thanks NeronLeVelu!):
sed -n '/^[a-f0-9]*$/{p;q}' file
Another approach is to let printf decide when the line is hexadecimal:
while read line
do
printf "%f\n" "0x"$line >/dev/null 2>&1 && echo "$line"
done < file
Based on Hexadecimal To Decimal in Shell Script, printf "%f" 0xNUMBER executes successfully if the number is indeed hexadecimal. Otherwise, it returns an error.
Hence, using printf ... >/dev/null 2>&1 && echo "$line" does not let printf print anything (redirects to /dev/null) but then prints the line if it was hexadecimal.
For your given file, it returns:
$ while read line; do printf "%f\n" "0x"$line >/dev/null 2>&1 && echo "$line"; done < a
234324fc234ba253069
Using egrep you can restrict your regex to select lines that only match valid hex characters i.e. [a-fA-F0-9]:
egrep '^[a-fA-F0-9]+$' file
234324fc234ba253069
I have a list of files (~1000) and there is 1 file per line in my text file named: 'files.txt'
I have a macro that looks something like the following:
#!/bin/sh
b=$(sed '${1}q;d' files.txt)
cat > MyMacro_${1}.C << +EOF
myFile = new TFile("/MYPATHNAME/$b");
+EOF
and I use this input script by doing
./MakeMacro.sh 1
and later I want to do
./MakeMacro.sh 2
./MakeMacro.sh 3
...etc
So that it reads the n'th line of my files.txt and feeds that string to my created .C macro.
So that it reads the n'th line of my files.txt and feeds that string to my created .C macro.
Given this statement and your tags, I'm going to answer using shell tools and not really address the issue of the .c macro.
The first line of your script contains a sed script. There are numerous ways to get the Nth line from a text file. The simplest might be to use head and tail.
$ head -n "${i}" files.txt | tail -n 1
This takes the first $i lines of files.txt, and shows you the last 1 lines of that set.
$ sed -ne "${i}p" files.txt
This use of sed uses -n to avoid printing by default, then prints the $ith line. For better performance, try:
$ sed -ne "${i}{p;q;}" files.txt
This does the same, but quits after printing the line, so that sed doesn't bother traversing the rest of the file.
$ awk -v i="$i" 'NR==i' files.txt
This passes the shell variable $i into awk, then evaluates an expression that tests whether the number of records processed is the same as that variable. If the expression evaluates true, awk prints the line. For better performance, try:
$ awk -v i="$i" 'NR==i{print;exit}' files.txt
Like the second sed script above, this will quit after printing the line, so as to avoid traversing the rest of the file.
Plenty of ways you could do this by loading the file into an array as well, but those ways would take more memory and perform less well. I'd use one-liners if you can. :)
To take any of these one-liners and put it into your script, you already have the notation:
if expr "$i" : '[0-9][0-9]*$' >/dev/null; then
b=$(sed -ne "${i}{p;q;}" files.txt)
else
echo "ERROR: invalid line number" >&2; exit 1
fi
If I am understanding you correctly, you can do a for loop in bash to call the script multiple times with different arguments.
for i in `seq 1 n`; do ./MakeMacro.sh $i; done
Based on the OP's comment, it seems that he wants to submit the generated files to Condor. You can modify the loop above to include the condor submission.
for i in `seq 1 n`; do ./MakeMacro.sh $i; condor_submit <OutputFile> ; done
i=0
while read file
do
((i++))
cat > MyMacro_${i}.C <<-'EOF'
myFile = new TFile("$file");
EOF
done < files.txt
Beware: you need tab indents on the EOF line.
I'm puzzled about why this is the way you want to do the job. You could have your C++ code read files.txt at runtime and it would likely be more efficient in most ways.
If you want to get the Nth line of files.txt into MyMacro_N.C, then:
{
echo
sed -n -e "${1}{s/.*/myFile = new TFILE(\"&\");/p;q;}" files.txt
echo
} > MyMacro_${1}.C
Good grief. The entire script should just be (untested):
awk -v nr="$1" 'NR==nr{printf "\nmyFile = new TFile(\"/MYPATHNAME/%s\");\n\n",$0 > ("MyMacro_"nr".C")}' files.txt
You can throw in a ;exit before the } if performance is an issue but I doubt if it will be.
We use some package called Autosys and there are some specific commands of this package. I have a list of variables which i like to pass in one of the Autosys commands as variables one by one.
For example one such variable is var1, using this var1 i would like to launch a command something like this
autosys_showJobHistory.sh var1
Now when I launch the below written command, it gives me the desired output.
echo "var1" | while read line; do autosys_showJobHistory.sh $line | grep 1[1..6]:[0..9][0..9] | grep 24.12.2012 | tail -1 ; done
But if i put the var1 in a file say Test.txt and launch the same command using cat, it gives me nothing. I have the impression that command autosys_showJobHistory.sh does not work in that case.
cat Test.txt | while read line; do autosys_showJobHistory.sh $line | grep 1[1..6]:[0..9][0..9] | grep 24.12.2012 | tail -1 ; done
What I am doing wrong in the second command ?
Wrote all of below, and then noticed your grep statement.
Recall that ksh doesn't support .. as an indicator for 'expand this range of values'. (I assume that's your intent). It's also made ambiguous by your lack of quoting arguments to grep. If you were using syntax that the shell would convert, then you wouldn't really know what reg-exp is being sent to grep. Always better to quote argments, unless you know for sure that you need the unquoted values. Try rewriting as
grep '1[1-6]:[0-9][0-9]' | grep '24.12.2012'
Also, are you deliberately using the 'match any char' operator '.' OR do you want to only match a period char? If you want to only match a period, then you need to escape it like \..
Finally, if any of your files you're processing have been created on a windows machine and then transfered to Unix/Linux, very likely that the line endings (Ctrl-MCtrl-J) (\r\n) are causing you problems. Cleanup your PC based files (or anything that was sent via ftp) with dos2unix file [file2 ...].
If the above doesn't help, You'll have to "divide and conquer" to debug your problem.
When I did the following tests, I got the expected output
$ echo "var1" | while read line ; do print "line=${line}" ; done
line=var1
$ vi Test.txt
$ cat Test.txt
var1
$ cat Test.txt | while read line ; do print "line=${line}" ; done
line=var1
Unrelated to your question, but certain to cause comment is your use of the cat commnad in this context, which will bring you the UUOC award. That can be rewritten as
while read line ; do print "line=${line}" ; done < Test.txt
But to solve your problem, now turn on the shell debugging/trace options, either by changing the top line of the script (the shebang line) like
#!/bin/ksh -vx
Or by using a matched pair to track the status on just these lines, i.e.
set -vx
while read line; do
print -u2 -- "#dbg: Line=${line}XX"
autosys_showJobHistory.sh $line \
| grep 1[1..6]:[0..9][0..9] \
| grep 24.12.2012 \
| tail -1
done < Test.txt
set +vx
I've added an extra debug step, the print -u2 -- .... (u2=stderror, -- closes option processing for print)
Now you can make sure no extra space or tab chars are creeping in, by looking at that output.
They shouldn't matter, as you have left your $line unquoted. As part of your testing, I'd recommend quoting it like "${line}".
Then I'd comment out the tail and the grep lines. You want to see what step is causing this to break, right? So does the autosys_script by itself still produce the intermediate output you're expecting? Then does autosys + 1 grep produce out as expected, +2 greps, + tail? You should be able to easily see where you're loosing your output.
IHTH
How can you limit the count of standard output characters that is redirected to file?
Other ways (external)
echo $out| head -c 20
echo $out | awk '{print substr($0,1,20) }'
echo $out | ruby -e 'print $_[0,19]'
echo $out | sed -r 's/(^.{20})(.*)/\1/'
You could use Command Substitution to wrap the output pre-redirection, then use the offset Parameter Expansion to limit the number of characters like so:
#!/bin/bash
limit=20
out=$(echo "this line has more than twenty characters in it")
echo ${out::limit} > /path/to/file
Proof of Concept
$ limit=20
$ out=$(echo "this line has more than twenty characters in it").
$ echo ${out::limit}
this line has more t
You can't do so directly into a file, but you can pipe through sed or head, etc. to pass on only part of the output. Or as #SiegeX says, capture the output in the shell (but I would be wary of that if the output mis likely to be large).