I want to replace a line with the $var.
runnew has
input= input/old/should/change;
replace= input/old/replace;
other = input/old/other;
replace_other= input/old/replace_other;
My output file should look like,
input= input/old/should/New;
replace= input/old/New_replace;
other = input/old/New_other;
replace_other= input/old/New_replace_other;
I want to replace "input =" by input = input/old/should/New;
I have used like,
if ($#ARGV != 0) {
die "\n********USAGE <cellname> <tech>********\n";
}
$newinput=$ARGV[0];
open(my $fh, "$runnew") or die "Could not open rerun.txt: $!";
while (<$fh>) {
system ( sed -i "/input=.*/c\input= $newinput" $runnew );
}
But there is error popping up "Scalar found where operator expected at run.pl" and its displaying sed line and asking " (Missing operator before $runnew?)."
When I used same sed on terminal its replacing the line .
Please can anyone point out where the error is ?
Yes Using Sed is simple but I have file with different lines and each line should be replaced .
Please let me knoe if you have better idea than this.
Thanks in advance.
system() takes a list of strings as its argument. You you need to put quotes around the command you pass it.
system ( "sed -i '/input=.*/c\input= $newinput' $runnew" );
But your code still looks very strange. You're running exactly the same sed command for every line in the input file. Is that what you meant to do?
It's not really clear what you're trying to do here. But I'm confident that the best approach would involve not using sed and using Perl to make your transformations.
Why do you want to call sed at all? Your requirement can be much easier handled in Perl directly:
add -i.bak to enable in-place replacement mode
use the first command line parameter as replacement string
remove it from the #ARGV array so it will not be interpreted as file
loop over all files on the command line
read line by line
apply substitution
print result
Perl automatically takes care of opening the files, writing to the correct file and renaming old files to .bak.
#!/usr/bin/perl -i.bak
use warnings;
use strict;
my($replacement) = shift(#ARGV);
while (<>) {
s/input=.*/input= $replacement/;
print;
}
exit 0;
Test run (taking an educated guess on your input data):
$ cat dummy1.txt.bak
input= test1
input= test2
$ cat dummy2.txt.bak
input= test3
input= test4
$ perl dummy.pl REPLACEMENT dummy1.txt dummy2.txt
$ cat dummy1.txt
input= REPLACEMENT
input= REPLACEMENT
$ cat dummy2.txt
input= REPLACEMENT
input= REPLACEMENT
or to use the contents of the file "rerun.txt":
$ perl dummy.pl REPLACEMENT $(cat rerun.txt)
I want to use gnuplot to draw figure from data file, say foo.data. Currently, I hardcoded the data file name in the command file, say foo.plt, and run command gnuplot foo.plg to plot data. However, I want to pass the data file name as a command argument, e.g. running command gnuplot foo.plg foo.data. How to parse the command line arguments in gnuplot script file? Thanks.
You can input variables via switch -e
$ gnuplot -e "filename='foo.data'" foo.plg
In foo.plg you can then use that variable
$ cat foo.plg
plot filename
pause -1
To make "foo.plg" a bit more generic, use a conditional:
if (!exists("filename")) filename='default.dat'
plot filename
pause -1
Note that -e has to precede the filename otherwise the file runs before the -e statements. In particular, running a shebang gnuplot #!/usr/bin/env gnuplot with ./foo.plg -e ... CLI arguments will ignore use the arguments provided.
You can pass arguments to a gnuplot script since version 5.0, with the flag -c. These arguments are accessed through the variables ARG0 to ARG9, ARG0 being the script, and ARG1 to ARG9 string variables. The number of arguments is given by ARGC.
For example, the following script ("script.gp")
#!/usr/local/bin/gnuplot --persist
THIRD=ARG3
print "script name : ", ARG0
print "first argument : ", ARG1
print "third argument : ", THIRD
print "number of arguments: ", ARGC
can be called as:
$ gnuplot -c script.gp one two three four five
script name : script.gp
first argument : one
third argument : three
number of arguments: 5
or within gnuplot as
gnuplot> call 'script.gp' one two three four five
script name : script.gp
first argument : one
third argument : three
number of arguments: 5
In gnuplot 4.6.6 and earlier, there exists a call mechanism with a different (now deprecated) syntax. The arguments are accessed through $#, $0,...,$9. For example, the same script above looks like:
#!/usr/bin/gnuplot --persist
THIRD="$2"
print "first argument : ", "$0"
print "second argument : ", "$1"
print "third argument : ", THIRD
print "number of arguments: ", "$#"
and it is called within gnuplot as (remember, version <4.6.6)
gnuplot> call 'script4.gp' one two three four five
first argument : one
second argument : two
third argument : three
number of arguments: 5
Notice there is no variable for the script name, so $0 is the first argument, and the variables are called within quotes. There is no way to use this directly from the command line, only through tricks as the one suggested by #con-fu-se.
You can also pass information in through the environment as is suggested here. The example by Ismail Amin is repeated here:
In the shell:
export name=plot_data_file
In a Gnuplot script:
#! /usr/bin/gnuplot
name=system("echo $name")
set title name
plot name using ($16 * 8):20 with linespoints notitle
pause -1
The answer of Jari Laamanen is the best solution. I want just explain how to use more than 1 input parameter with shell variables:
output=test1.png
data=foo.data
gnuplot -e "datafile='${data}'; outputname='${output}'" foo.plg
and foo.plg:
set terminal png
set outputname
f(x) = sin(x)
plot datafile
As you can see,more parameters are passed with semi colons (like in bash scripts), but string variables NEED to be encapsuled with ' ' (gnuplot syntax, NOT Bash syntax)
You may use trick in unix/linux environment:
in gnuplot program: plot "/dev/stdin" ...
In command line: gnuplot program.plot < data.dat
This question is well answered but I think I can find a niche to fill here regardless, if only to reduce the workload on somebody googling this like I did. The answer from vagoberto gave me what I needed to solve my version of this problem and so I'll share my solution here.
I developed a plot script in an up-to-date environment which allowed me to do:
#!/usr/bin/gnuplot -c
set terminal png truecolor transparent crop
set output ARG1
set size 1, 0.2
rrLower = ARG2
rrUpper = ARG3
rrSD = ARG4
resultx = ARG5+0 # Type coercion required for data series
resulty = 0.02 # fixed
# etc.
This executes perfectly well from command-line in an environment with a recent gnuplot (5.0.3 in my case).
$ ./plotStuff.gp 'output.png' 2.3 6.7 4.3 7
When uploaded to my server and executed, it failed because the server version was 4.6.4 (current on Ubuntu 14.04 LTS).
The below shim solved this problem without requiring any change to the original script.
#!/bin/bash
# GPlot v<4.6.6 doesn't support direct command line arguments.
#This script backfills the functionality transparently.
SCRIPT="plotStuff.gp"
ARG1=$1
ARG2=$2
ARG3=$3
ARG4=$4
ARG5=$5
ARG6=$6
gnuplot -e "ARG1='${ARG1}'; ARG2='${ARG2}'; ARG3='${ARG3}'; ARG4='${ARG4}'; ARG5='${ARG5}'; ARG6='${ARG6}'" $SCRIPT
The combination of these two scripts allows parameters to be passed from bash to gnuplot scripts without regard to the gnuplot version and in basically any *nix.
You could even do some shell magic, e.g. like this:
#!/bin/bash
inputfile="${1}" #you could even do some getopt magic here...
################################################################################
## generate a gnuplotscript, strip off bash header
gnuplotscript=$(mktemp /tmp/gnuplot_cmd_$(basename "${0}").XXXXXX.gnuplot)
firstline=$(grep -m 1 -n "^#!/usr/bin/gnuplot" "${0}")
firstline=${firstline%%:*} #remove everything after the colon
sed -e "1,${firstline}d" < "${0}" > "${gnuplotscript}"
################################################################################
## run gnuplot
/usr/bin/gnuplot -e "inputfile=\"${inputfile}\"" "${gnuplotscript}"
status=$?
if [[ ${status} -ne 0 ]] ; then
echo "ERROR: gnuplot returned with exit status $?"
fi
################################################################################
## cleanup and exit
rm -f "${gnuplotscript}"
exit ${status}
#!/usr/bin/gnuplot
plot inputfile using 1:4 with linespoints
#... or whatever you want
My implementation is a bit more complex (e.g. replacing some magic tokens in the sed call, while I am already at it...), but I simplified this example for better understanding.
You could also make it even simpler.... YMMV.
In the shell write
gnuplot -persist -e "plot filename1.dat,filename2.dat"
and consecutively the files you want.
-persist is used to make the gnuplot screen stay as long as the user doesn't exit it manually.
#vagoberto's answer seems the best IMHO if you need positional arguments, and I have a small improvement to add.
vagoberto's suggestion:
#!/usr/local/bin/gnuplot --persist
THIRD=ARG3
print "script name : ", ARG0
print "first argument : ", ARG1
print "third argument : ", THIRD
print "number of arguments: ", ARGC
which gets called by:
$ gnuplot -c script.gp one two three four five
script name : script.gp
first argument : one
third argument : three
number of arguments: 5
for those lazy typers like myself, one could make the script executable (chmod 755 script.gp)
then use the following:
#!/usr/bin/env gnuplot -c
THIRD=ARG3
print "script name : ", ARG0
print "first argument : ", ARG1
print "third argument : ", THIRD
print "number of arguments: ", ARGC
and execute it as:
$ ./imb.plot a b c d
script name : ./imb.plot
first argument : a
third argument : c
number of arguments: 4
Yet another way is this:
You have a gnuplot script named scriptname.gp:
#!/usr/bin/gnuplot -p
# This code is in the file 'scriptname.gp'
EPATH = $0
FILENAME = $1
plot FILENAME
Now you can call the gnuplot script scriptname.gp by this convoluted peace of syntax:
echo "call \"scriptname.gp\" \"'.'\" \"'data.dat'\"" | gnuplot
I have done a shell script that gets the output of a .jar file and assign in to a variable.
rewards_generator.sh
APP_ROOT=/home/testApps/
JAR=${APP_ROOT}ClusterGenerator/generator.jar
#get clusters
clusters=$(loadClusters $1)
for i in `echo $clusters | sed 's/,/ /g'`
do
#pull cluster records from database and save query return status to $x
x=$(/usr/IBM/WebSphere/ProcServer/java/bin/java ${JAR} ${i/-/_} 2>&1)
done
Basically, what I've done to the java app is to System.out.print the query return status. Then used the 2>&1 in bash in order to get into the output stream and assign the value to a shell script variable.
Now how can I get the return value of a perl script and assign it to a shell script variable? Is it the same as the one I've done above or is there any other approach to do this?
You can use backticks to record the output of an external command in a bash script.
Here's a simple example:
#!/bin/bash
# Execute the script, recording output to a variable
x=`/path/to/script.pl`
# Display or act on the output some time later
echo "script output: $x"
Now how can I get the return value of a perl script and assign it to a shell script variable?
#! /bin/bash
perl script.pl
return_value=$?
I have some output data from some Bash Shell commands. The output is delimited line by line with "\n" or "\0". I would like to know that is there any way to pipe the output into Perl and process the data line by line within Perl (just like piping the output to awk, but in my case it is in the Perl context.). I suppose the command may be something like this :
Bash Shell command | perl -e 'some perl commands' | another Bash Shell command
Suppose I want to substitute all ":" character to "#" character in a "line by line" basis (not a global substitution, I may use a condition, e.g. odd or even line, to determine whether the current line should have the substitution or not.), then how could I achieve this.
See perlrun.
perl -lpe's/:/#/g' # assumes \n as input record separator
perl -0 -lpe's/:/#/g' # assumes \0 as input record separator
perl -lne'if (0 == $. % 2) { s/:/#/g; print; }' # modify and print even lines
Yes, Perl may appear at any place in a pipeline, just like awk.
The command line switch -p (if you want automatic printing) or -n (if you don't want it) will do what you want. The line contents are in $_ so:
perl -pe's/\./\#/g'
would be a solution. Generally, you want to read up on the '<>' (diamond) operator which is the way to go for non-oneliners.
This has been driving me nuts for hours now.
Consider the following test script in perl:
(hello.pl)
#!/usr/bin/perl
print "----------------------------------\n";
$numArgs = $#ARGV + 1;
print "thanks, you gave me $numArgs command-line arguments:\n";
foreach $argnum (0 .. $#ARGV) {
print "$ARGV[$argnum]\n";
}
Ok, it simply prints out the command line arguments given to the script.
For instance:
$ ./hello.pl apple pie
----------------------------------
thanks, you gave me 2 command-line arguments:
apple
pie
I can give the script a single argument with a space by surrounding the words with double quotes:
$ ./hello.pl "apple pie"
----------------------------------
thanks, you gave me 1 command-line arguments:
apple pie
Now I want to use this script in a shell script. I've set up the shell script like this:
#!/bin/bash
PARAM="apple pie"
COMMAND="./hello.pl \"$PARAM\""
echo "(command is $COMMAND)"
$COMMAND
I am calling the hello.pl with the same params and escaped quotes.
This script returns:
$ ./test.sh
(command is ./hello.pl "apple pie")
----------------------------------
thanks, you gave me 2 command-line arguments:
"apple
pie"
Even though the $COMMAND variable echoes the command exactly like the way I ran the perl script from the command line the second time, this time it does not want to see the apple pie as a single argument.
Why not?
This looks like the problem described in the Bash FAQ as: I'm trying to put a command in a variable, but the complex cases always fail!
The answer to that FAQ suggests a number of possible solutions - I hope that's of use.
The issue of the 2 command-line arguments
"apple
pie"
is due to shell expansion with the IFS shell variable being set to have a space as value.
printf '%q\n' "$IFS" # show value of IFS variable
You may use xargs & sh -c '...code...' to mimic / re-enable ordinary parameter parsing.
PARAM="'apple pie'"
printf '%s' "$PARAM" | xargs sh -c './hello.pl "$#"' argv0
Another option may be to write a few lines of C (like in shebang.c)!
http://www.semicomplete.com/blog/geekery/shebang-fix.html
You should try eval $COMMAND instead of simply $COMMAND.