You want to test the existence with -f and then create a file. But what happens, if between test and creation another task creates the file? mktemp can resolve this problem: filename=$( mktemp ./file1-XXXXXXXXXX ) || exit 1 In this case, an empty file is created (like using touch). The XXXXXXXXXX part is replaced by … Read more
we cannot use any 3rd party tools which are not usually present on systems Given that we don’t know what “systems” you’re using, this isn’t a very useful restriction to tell us about. Perl has several JSON parsers available and since Perl 5.14 (which was released in May 2011) one of them (JSON::PP) has been … Read more
<(command) is a bashism called Process substitution You have to run your script with bash, eg do bash script.bash Or if you want to use sh, you could write the results to a file, like this : grep eth0 /proc/net/dev > file1 sleep 1 ; grep eth0 /proc/net/dev > file2 diff file1 file2
If you want to do it in pure bash, use the following script: #!/bin/bash while read line; do line=( ${line//[:]/ } ) for i in “${!line[@]}”; do [ ! -z “${line[$i]##*[!0-9]*}” ] && printf “integer” || printf “string” [ “$i” -ne $(( ${#line[@]} – 1)) ] && printf “:” || echo done done < $1 … Read more
You don’t show much effort to let us help you solving this. But since I’m learning bash scripting, I took your question as practicing. So… here is a bash script to rename duplicated files. /!\ The renamed files will be in the folder of first argument. So, in your case, you’ll have to launch it … Read more
In POSIX grep, -v is a matching control option to invert match. In this usage case, it is telling grep to match all lines that do NOT contain the string “:0” For more information, man grep
You can also consider using groupby If your data is already in this format: [ [‘CZ’, ’12/27/07 3:55 PM’, ‘1198788900’, ‘42345’, ‘42346’,], [‘CZ’, ’12/27/07 5:30 PM’, ‘1198794600’, ‘42346’, ‘42300’,], [‘CZ’, ’12/27/07 7:05 PM’,’1198800300′, ‘42300’, ‘42000’,], [‘JB’, ’12/27/07 7:05 PM’,’1198800300′, ‘13722’, ‘13500’,], [‘I’, ’12/27/07 7:05 PM’, ‘1198800300’, ‘4475’, ‘4572’] ] Then you can do this: #truncate … Read more
From what we can discern of this question, you’re attempting to create a programmatic rule to rename files ending in extensions stdout-captured, stderr-captured, and status-captured (assuming one typo) into files ending in extensions stdout-expected, stderr-expected, and status-expected, respectively. Obviously, if each of these definitions is inclusive of exactly one file, a rote mv may be … Read more
It’s not impossible. Use the read command. read -p “My name is ” name echo “Nice to meet you $name”
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