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Editorial Team
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Asked: 2026-06-13T00:27:37+00:00

I need to use an awk script to extract some information from a file.

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I need to use an awk script to extract some information from a file.
I have a title line which has 11 field and I split it to an array called titleList.

Student Number:Name:Lab1:Lab2:Lab3:Lab4:Lab5:Lab6:Exam1:Exam2:Final

After finding a proper line I need to print the fields which proceeds by the titles for example if the result is :

92839342:Robert Bloomingdale:9:26:18:22:9:12:25:39:99

I must print it in this way:

Student Number:92839342 Name:Robert Bloomingdale Lab1:9 Lab2:26 Lab3:18
Lab4:22 Lab5:9 Lab6:12 Exam1:25 Exam2:39 Final:99

I use a for loop to manage it:

for (i=0 ;i<=NF ;i++)
{
    printf "%s %s %s %s",titleList[i],":",$i," "
}

everything look good except the result which has 2 problems:
first there is an extra space between each result and second the last field of the searched line is missing

    Student Number : 92839342  Name : Robert Bloomingdale  Lab1 : 9  Lab2 : 26
    Lab3:18  Lab4 : 22  Lab5 : 9  Lab6 : 12  Exam1 : 25  Exam2 : 39  Final

what should I do?
is there any problem with \n at the end of the search result?

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1 Answer

  1. Editorial Team

    You can correct the amount of extra whitespace between fields by correcting the printf statement:

    awk -F ":" 'NR == 1 { split($0, array, FS) } NR >= 2 { for (i=1; i<=NF; i++) printf "%s:%s ", array[i], $i; printf "\n" }' file.txt

    Contents of file.txt:

    Student Number:Name:Lab1:Lab2:Lab3:Lab4:Lab5:Lab6:Exam1:Exam2:Final
92839342:Robert Bloomingdale:9:26:18:22:9:12:25:39:99

    Results:

    Student Number:92839342 Name:Robert Bloomingdale Lab1:9 Lab2:26 Lab3:18 Lab4:22 Lab5:9 Lab6:12 Exam1:25 Exam2:39 Final:99

    EDIT:

    Also, your missing the last value because the file you’re working with probably has windows newline endings. To fix this, run: dos2unix file.txt before running your awk code. Alternatively, you can set awk‘s record separater so that it understands newline endings:

    awk 'BEGIN { RS="\r\n"; FS=":" } NR == 1 { split($0, array, FS) } NR >= 2 { for (i=1; i<=NF; i++) printf "%s:%s ", array[i], $i; printf "\n" }' file.txt

    EDIT:

    The above requires GNU awk, split() splits on the FS by default so no need to use that as an arg, it’s common to use “next” rather than specifying opposite conditions, and it’s common to use print “” instead of printf “\n” so you use the ORS setting rather than hard-coding it’s value in output statements. So, the above should be tweaked to:

    gawk 'BEGIN { RS="\r\n"; FS=":" } NR == 1 { split($0, array); next } { for (i=1; i<=NF; i++) printf "%s:%s ", array[i], $i; print "" }' file.txt
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