I want to get the part of the filename by using AWK command. For,example my filename will be like ABC_20100702001500.CSV. I want to get YYYYMMDD format from my filename to create a directory. I tried with
name=$(awk -F"." '{print $f}' | awk -F"_" '{print $NF}').
But its shows error like syntax error near unexpected token `name=awk'. How could I resolve the problem. Please correct me with correct syntax.
You may want to do this in Bash alone.
Given:
$ st="ABC_20100702001500.CSV"
You can use parameter expansion to remove the front and back portion:
$ tmp="${st#*_}"
$ echo "${tmp%.*}"
20100702001500
Or, Bash has regex capability as well:
$ [[ $st =~ ^[^_]*_([^.]+) ]] && echo ${BASH_REMATCH[1]}
20100702001500
Or, use sed if you have an older non Bash shell:
$ echo "$st" | sed -E 's/^[^_]*_//; s/\..*$//'
20100702001500
Related
I'm trying to figure out a command to parse the following file content:
Operation=GET
Type=HOME
Counters=CacheHit=0,Exception=1,Validated=0
I need to extract Exception=1 into its own line. I'm fiddling with awk, sed and grep but not making much progress. Does anyone have any tips on using any unix command to perform this?
Thanks
Since your file is close to bash syntax, there is a fun little trick you can do to make bash itself parse the file. First, use some program like tr to transform the input into a something bash can parse, and then "source" that, which will create shell variables you can expand later to get the values.
source <(tr , $'\n' < file_name_goes_here)
echo $Exception
Many ways to do this. Here is one assuming the file is called "file.txt". Grab the line you want, replace everything from the start of the line up to Except with just Except, then pull out the first field using comma as the delimiter.
$ grep Exception file.txt | sed 's/.*Except/Except/g' | cut -d, -f 1
Exception=1
If you wanted to use gawk:
$ grep Exception file.txt | sed 's/.*Except/Except/g' | gawk -F, '{print $1}'
Exception=1
or just using grep and sed:
$ grep Exception file.txt | sed 's/.*\(Exception=[0-9]*\).*/\1/g'
Exception=1
or as #sheltter reminded me:
$ egrep -o "Exception=[0-9]+" file.txt
Exception=1
No need to use a mix of commands.
awk -F, 'NR==2 {print RS$1}' RS="Exception" file
Exception=1
Here we split the line by the keyword we look for RS="Exception"
If the line has two record (only when keyword is found), then
print first field, separated using command, with Record selector.
PS This only works if you have one Exception field
Good day,
I have a simple UNIX script test.sh
I need to substitute the value of a variable.
This variable contains a directory path.
My test.sh script
#!/bin/sh
filepath="/host/messages/in/documents"
archivePath=`${filepath/\/in/\/archive/}`
echo "archive path is " $archivePath
I get a "bad substitution" error when I run it.
The required output for archivePath should be:
/host/messages/archive/documents
What am I doing wrong and what could be a possible solution?
Must use bash (or ksh or zsh), use correct syntax ${varname/pattern/replacement} and escape / by \ in pattern and replacement.
#!/bin/bash
filepath="/host/messages/in/documents"
archivePath="${filepath/\/in\//\/archive\/}"
echo "archive path is $archivePath"
found a solution with sed:
#!/bin/sh
filepath="/host/messages/in/documents"
echo $filepath | sed -e %s/in/archive/g
archivePath=`echo $filepath | sed -e s/in/archive/g`
echo "archive path is $archivePath"
Im trying to get the following script to work, but Im having some issues:
g++ -g -c $1
DWARF=echo $1 | sed -e `s/(^.+)\.cpp$/\1/`
and Im getting -
./dcompile: line 3: test3.cpp: command not found
./dcompile: command substitution: line 3: syntax error near unexpected token `^.+'
./dcompile: command substitution: line 3: `s/(^.+)\.cpp$/\1/'
sed: option requires an argument -- 'e'
and then bunch of stuff on sed usage. What I want to do is pass in a cpp file and then extract the file name without the .cpp and put it into the variable DWARF. I would also like to later use the variable DWARF to do the following -
readelf --debug-dump=info $DWARF+".o" > $DWARF+".txt"
But Im not sure how to actually do on the fly string concats, so please help with both those issues.
You actually need to execute the command:
DWARF=$(echo $1 | sed -e 's/(^.+)\.cpp$/\1/')
The error message is a shell error because your original statement
DWARF=echo $1 | sed -e `s/(^.+)\.cpp$/\1/`
is actually parsed like this
run s/(^.+)\.cpp$/\1/
set DWARF=echo
run the command $1 | ...
So when it says test3.cpp: command not found I assume that you are running with argument test3.cpp and it's literally trying to execute that file
You also need to wrap the sed script in single quotes, not backticks
In BASH you can crop off the extension from $1 by
${1%*.cpp}
if you need to set the DWARF var use
DWARF="${1%*.cpp}"
or just reference $1 as
readelf --debug-dump=info "${1%*.cpp}.o" > "${1%*.cpp}.txt"
which will chop off the rightmost .cpp so test.cpp.cpp will be test.cpp
You can use awk for this:
$ var="testing.cpp"
$ DWARF=$(awk -F. '{print $1}' <<< $var)
$ echo "$DWARF"
testing
I am having a log file a.log and i need to extract a piece of information from it.
To locate the start and end line numbers of the pattern i am using the following.
start=$(sed -n '/1112/=' file9 | head -1)
end=$(sed -n '/true/=' file9 | head -1)
i need to use the variables (start,end) in the following command:
sed -n '16q;12,15p' orig-data-file > new-file
so that the above command appears something like:
sed -n '($end+1)q;$start,$end'p orig-data-file > new-file
I am unable to replace the line numbers with the variables. Please suggest the correct syntax.
Thanks,
Rosy
When I realized how to do it, I was looking for anyway to get line number into a file containing the requested info, and display the file from that line to EOF.
So, this was my way.
with
PATTERN="pattern"
INPUT_FILE="file1"
OUTPUT_FILE="file2"
line number of first match of $PATTERN into $INPUT_FILE can be retrieved with
LINE=`grep -n ${PATTERN} ${INPUT_FILE} | awk -F':' '{ print $1 }' | head -n 1`
and the outfile will be the text from that $LINE to EOF. This way:
sed -n ${LINE},\$p ${INPUT_FILE} > ${OUTPUT_FILE}
The point here, is the way how can variables be used with command sed -n:
first witout using variables
sed -n 'N,$p' <file name>
using variables
LINE=<N>; sed -n ${LINE},\$p <file name>
Remove the single quotes thus. Single quotes turn off the shell parsing of the string. You need shell parsing to do the variable string replacements.
sed -n '('$end'+1)q;'$start','$end''p orig-data-file > new-file
I need to get the records from a text file in Unix. The delimiter is multiple blanks. For example:
2U2133 1239
1290fsdsf 3234
From this, I need to extract
1239
3234
The delimiter for all records will be always 3 blanks.
I need to do this in an unix script(.scr) and write the output to another file or use it as an input to a do-while loop. I tried the below:
while read readline
do
read_int=`echo "$readline"`
cnt_exc=`grep "$read_int" ${Directory path}/file1.txt| wc -l`
if [ $cnt_exc -gt 0 ]
then
int_1=0
else
int_2=0
fi
done < awk -F' ' '{ print $2 }' ${Directoty path}/test_file.txt
test_file.txt is the input file and file1.txt is a lookup file. But the above way is not working and giving me syntax errors near awk -F
I tried writing the output to a file. The following worked in command line:
more test_file.txt | awk -F' ' '{ print $2 }' > output.txt
This is working and writing the records to output.txt in command line. But the same command does not work in the unix script (It is a .scr file)
Please let me know where I am going wrong and how I can resolve this.
Thanks,
Visakh
The job of replacing multiple delimiters with just one is left to tr:
cat <file_name> | tr -s ' ' | cut -d ' ' -f 2
tr translates or deletes characters, and is perfectly suited to prepare your data for cut to work properly.
The manual states:
-s, --squeeze-repeats
replace each sequence of a repeated character that is
listed in the last specified SET, with a single occurrence
of that character
It depends on the version or implementation of cut on your machine. Some versions support an option, usually -i, that means 'ignore blank fields' or, equivalently, allow multiple separators between fields. If that's supported, use:
cut -i -d' ' -f 2 data.file
If not (and it is not universal — and maybe not even widespread, since neither GNU nor MacOS X have the option), then using awk is better and more portable.
You need to pipe the output of awk into your loop, though:
awk -F' ' '{print $2}' ${Directory_path}/test_file.txt |
while read readline
do
read_int=`echo "$readline"`
cnt_exc=`grep "$read_int" ${Directory_path}/file1.txt| wc -l`
if [ $cnt_exc -gt 0 ]
then int_1=0
else int_2=0
fi
done
The only residual issue is whether the while loop is in a sub-shell and and therefore not modifying your main shell scripts variables, just its own copy of those variables.
With bash, you can use process substitution:
while read readline
do
read_int=`echo "$readline"`
cnt_exc=`grep "$read_int" ${Directory_path}/file1.txt| wc -l`
if [ $cnt_exc -gt 0 ]
then int_1=0
else int_2=0
fi
done < <(awk -F' ' '{print $2}' ${Directory_path}/test_file.txt)
This leaves the while loop in the current shell, but arranges for the output of the command to appear as if from a file.
The blank in ${Directory path} is not normally legal — unless it is another Bash feature I've missed out on; you also had a typo (Directoty) in one place.
Other ways of doing the same thing aside, the error in your program is this: You cannot redirect from (<) the output of another program. Turn your script around and use a pipe like this:
awk -F' ' '{ print $2 }' ${Directory path}/test_file.txt | while read readline
etc.
Besides, the use of "readline" as a variable name may or may not get you into problems.
In this particular case, you can use the following line
sed 's/ /\t/g' <file_name> | cut -f 2
to get your second columns.
In bash you can start from something like this:
for n in `${Directoty path}/test_file.txt | cut -d " " -f 4`
{
grep -c $n ${Directory path}/file*.txt
}
This should have been a comment, but since I cannot comment yet, I am adding this here.
This is from an excellent answer here: https://stackoverflow.com/a/4483833/3138875
tr -s ' ' <text.txt | cut -d ' ' -f4
tr -s '<character>' squeezes multiple repeated instances of <character> into one.
It's not working in the script because of the typo in "Directo*t*y path" (last line of your script).
Cut isn't flexible enough. I usually use Perl for that:
cat file.txt | perl -F' ' -e 'print $F[1]."\n"'
Instead of a triple space after -F you can put any Perl regular expression. You access fields as $F[n], where n is the field number (counting starts at zero). This way there is no need to sed or tr.