I am trying to trim this, which is stored in a variable called $line.
[2012-06-18 10:37:09,026 (there is a lot of text after this, i just cut it out)
I am new to shell scripting and this is the code that i have
errortime= $line | cut -c2-10;
it is giving me an error, what is the correct code to pull the date out of the variable $line.
did you want:
errortime=`echo $line | cut -c2-20`
instead?
Edit:
If you are using ksh, that line needs to look like this:
errortime=$(echo $line | cut -c2-20)
Related
I'm new to sed and have been trying to use it with no luck yet in this case.
I'm reading through a log file and I store the prior line into a variable so that I can extract out the date if needed.
variable string example:
jcl/jclnt.log-[05/06/20 16:42:52.964]:jclnt ST:
I'm only wanting the date and timestamp in the square brackets. I want to ignore the characters before and after. The date and time format are always the same length and format. I can match on it with a regex, just not sure how to extract it from a variable into a new variable with only the data inside the square brackets.
I tried something like this:
priordate= echo "$prior" | awk -F'[][]' '{print $2}'
But that didn't work.
It should work if you remove the space before your echo.
echo "jcl/jclnt.log-[05/06/20 16:42:52.964]:jclnt ST:" | awk -F'[][]' '{print $2}'
05/06/20 16:42:52.964
and then make the statement thus: priordate=$(echo ...)
You can use Bash's native regular expression matching. This is a quick and dirty regular expression that just relies on capturing whatever is between [ and ]. You can certainly make it more specific if necessary.
#!/bin/bash
s="jcl/jclnt.log-[05/06/20 16:42:52.964]:jclnt ST:"
pattern="\[(.*)\]"
if [[ "${s}" =~ $pattern ]]
then
date_time="${BASH_REMATCH[1]}"
fi
echo "${date_time}"
Output:
05/06/20 16:42:52.964
I have a file ($ScriptName). I want the first 2 charactors of every line to be in a list (Starters). I am using a bash script.
How would I do this?
I have declared my array like this:
array=() #Empty array
Using guidence from this: https://opensource.com/article/18/5/you-dont-know-bash-intro-bash-arrays
I am using manjaro 19 and the latest kernel.
To get the first two characters from each line, you can use
cut -c1,2 "$ScriptName"
-c1,2 means "output characters in positions 1 and 2"
I'm not sure what you mean by a "list". If you just want to create a file with the results, use redirection:
cut -c1,2 "$ScriptName" > Starters
If you want to populate an array, just use
while IFS= read -r starter ; do Starters+=("$starter") ; done < <(cut -c1,2 "$ScriptName")
Moreover, if you're interested in letters rather than characters, you can use sed to remove non-letters from each line and then use the solution shown above.
sed 's/[^[:alpha:]]//g' "$ScriptName" | cut -c1,2
Try this Shellcheck-clean (except for a missing initialization of ScriptName) pure Bash code:
Starters=()
while IFS= read -r line || [[ -n $line ]]; do
Starters+=( "${line:0:2}" )
done < "$ScriptName"
See Arrays [Bash Hackers Wiki] for information about using arrays in Bash.
See BashFAQ/001 (How can I read a file (data stream, variable) line-by-line (and/or field-by-field)?)
for information about reading files line-by-line in Bash.
See Removing part of a string (BashFAQ/100 (How do I do string manipulation in bash?)) (particularly the bit about "range notation") for an explanation of ${line:0:2}".
The mapfile bash built-in command combined with cut makes it simple:
cut -c1,2 "$ScriptName" | mapfile Starters
This question already has answers here:
How do I split a string on a delimiter in Bash?
(37 answers)
Closed 4 years ago.
I am new to shell scripting, can you please help with below requirement, thanks.
$AU_NAME=AU_MSM3-3.7-00.01.02.03
#separate the string after last "-", with "." as delimiter
#that is, separate "00.01.02.03" and print/save as below.
major=00
minor=01
micro=02
build=03
First, note that you don't use $ when assigning to a parameter in the shell. Your first line should be just this:
AU_NAME=AU_MSM3-3.7-00.01.02.03
The $ is used to get the value of the parameter once assigned. And the bit after the $ can be an expression in curly braces with extra stuff besides just the name, allowing you to perform various operations on the value. For example, you can do something like this:
IFS=. read major minor micro build <<EOF
${AU_NAME##*-}
EOF
where the ##*- strips off everything from the beginning of the string through the last '-', leaving just "00.01.02.03", and the IFS (Internal Field Separator) parameter tells the shell where to break the string into fields.
In bash, zsh, and ksh93+, you can get that onto one line by shortening the here-document to a here-string:
IFS=. read major minor micro build <<<"${AU_NAME##*-}"
More generally, in those same shells, you can split into an arbitrarily-sized array instead of distinct variables:
IFS=. components=(${AU_NAME##*-})
(Though that syntax won't work in especially-ancient versions of ksh; in them you have to do this instead:
IFS=. set -A components ${AU_NAME##*-}
)
That gets you this equivalence (except in zsh, which by default numbers the elements 1-4 instead of 0-3):
major=${components[0]}
minor=${components[1]}
micro=${components[2]}
build=${components[3]}
In bash, you can do something like this:
version=$(echo $AU_NAME | grep -o '[^-]*$')
major=$(echo $version | cut -d. -f1)
minor=$(echo $version | cut -d. -f2)
micro=$(echo $version | cut -d. -f3)
build=$(echo $version | cut -d. -f4)
The grep call uses -o which outputs only the matching part of the line. The match itself is every non-hyphen character to the end of the line.
The cut command uses the delimeter . (-d.), and uses -f to select individual fields.
It's a little clunky. I'm sure there are probably better ways to achieve this, but you can do quite a lot with grep and cut alone so they're handy tools to have in your arsenal.
You can use parameter expansion and the special IFS variable.
#! /bin/bash
AU_NAME=AU_MSM3-3.7-00.01.02.03
IFS=. VER=(${AU_NAME##*-})
for i in {0..3} ; do
echo ${VER[i]}
done
major=${VER[0]}
minor=${VER[1]}
micro=${VER[2]}
build=${VER[3]}
BTW, in an assignment, do not start the variable on the left hand side with a dollar sign.
I have a wierd situation. I am trying to cut some info from a file and everything works fine when I run the command straight into the terminal, but as soon as I make it a variable in a script it returns a mixture of what it should cut and a list of the files in the current directory.
cat query.sql | cut -d':' -f3,4
works but...
QUERY_SQL="query.sql"
MYSQL_COMMAND=`cat $QUERY_SQL | cut -d':' -f3,4`
echo $MYSQL_COMMAND
returns the wierd output mentioned above.
What am I doing wrong?
EDIT:
The query file looks something like this...
email#somehwhere.com:3:SQL CODE
I suspect something in the contents of MYSQL_COMMAND is being interpreted as a filename glob pattern. Try changing
MYSQL_COMMAND=`cat $QUERY_SQL | cut -d':' -f3,4`
echo $MYSQL_COMMAND
to
MYSQL_COMMAND="$(cut -d: -f3,4 < "$QUERY_SQL")"
printf '%s\n' "$MYSQL_COMMAND"
Best defensive coding practice for shell is to put double quotes around every variable substitution, unless you know for a fact that you need word splitting and glob expansion to happen after a particular substitution. Changing echo to printf '%s\n' avoids a related set of problems. I can never remember whether you actually need double quotes around $(...) in a variable assignment, so I put them in just to be safe.
I have a file with the following text
and I want to get the 1st,2nd,and 4th value only**1343311371204**,*****210*****,http://172.16.1.139/CC_WEB/jsp/Login.jsp,**200**,OK,true,9,9
1343311371044,304,http://172.16.1.139/CC_WEB/jsp/Login.jsp,200,OK,true,8,8
1343311371109,239,http://172.16.1.139/CC_WEB/jsp/Login.jsp,200,OK,true,8,8
1343311371083,263,http://172.16.1.139/CC_WEB/jsp/Login.jsp,200,OK,true,8,8 in every line. So How can I do it?
Using cut
cut -d, -f1,2,4 your_file should do it fine.
Using read (bash builtin function)
Using read in a while loop, you can use variables to do things with those values :
while IFS=',' read timestamp value2 url code remains ; do
# use those variables
done < your_file`
awk -F, '{print $1,$2,$4}' your_file