1

I am given a file containing the md5 values for files within the same folder. The information is in the file md5checksums.txt in the following format:

b0da7ead9d82a3494d7e0a7099871ef4  ./GCF_000959505.1_ASM95950v1_assembly_report.txt
7ff32cbb16daf46c87b3546ad576ff66  ./GCF_000959505.1_ASM95950v1_assembly_stats.txt
034081da3aa0708f06c2ec1129e4aca9  ./GCF_000959505.1_ASM95950v1_cds_from_genomic.fna.gz

I want to do md5 checks for all the files. I got this command:

awk '{system("md5 "$2)}' md5checksums.txt

But this just gets the md5 values

MD5 (./GCF_000959505.1_ASM95950v1_assembly_report.txt) = b0da7ead9d82a3494d7e0a7099871ef4
MD5 (./GCF_000959505.1_ASM95950v1_assembly_stats.txt) = 7ff32cbb16daf46c87b3546ad576ff66
MD5 (./GCF_000959505.1_ASM95950v1_cds_from_genomic.fna.gz) = 3a30966523a36368ab432f666001f80a

I would like to extract the calculated md5 against the first column of md5checksums.txt I thought I could do something like an awk inside an awk, but I can't get it to work:

awk '{system("md5 "$2" | awk HERE EVALUATE RESULTS AND CHECK IF EQUAL TO $1")}' md5checksums.txt
  • 3
    BSD md5 vs GNU md5sum output. Give md5 the -r option to produce the same output format as md5sum. – Mark Plotnick Dec 19 '18 at 16:52
  • Great, but I still have to parse the results since they are given in 2 columns – Julio Diaz Dec 19 '18 at 16:56
  • do you want to check file againt their md5 sum ? Yes=> md5sum -r Or see if same file comme with new name ? – Archemar Dec 19 '18 at 17:14
  • I suspect that this an escaping problem, you need to escape the $ to stop it being interpreted by the outer awk. I am sure there are better answers though. – ctrl-alt-delor Dec 19 '18 at 17:40
5

I'm a bit confused as to why you involve awk in this.

To verify the MD5 checksums in a file produced by GNU md5sum, you do

md5sum -c file.txt

Or, on an OpenBSD or NetBSD system whose md5 utility supports -c filename (not FreeBSD or macOS):

md5 -c file.txt

In your case, file.txt would be your md5checksums.txt file.

  • How would I check the resulting value to the one given in a file along the md5s of other files? I should have made it clear that I would like to check the md5 values for all the files in the folder. – Julio Diaz Dec 19 '18 at 16:50
  • @JulioDiaz I don't thing I understand that question. In my example, file.txt is the file that contains the MD5 checksums and pathnames. md5sum -c file.txt will calculate the MD5 checksums of the files listed and compare them to the corresponding pre-calculated checksums. You probably just need to use md5checksums.txt instead of file.txt. – Kusalananda Dec 19 '18 at 16:55
  • I see. Is there a homologue to -c in md5? – Julio Diaz Dec 19 '18 at 16:59
  • @JulioDiaz You haven't yet said what type of Unix you are working with. – Kusalananda Dec 19 '18 at 17:07
  • Im working from OSX – Julio Diaz Dec 19 '18 at 17:10

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