zcat - expand a gzip file to standard output (= gzip -dc)

Options you will use

-c, --stdout

write on standard output, keep original files unchanged

-d, --decompress

decompress

-f, --force

force overwrite of output file and compress links

-k, --keep

keep (don't delete) input files

-l, --list

list compressed file contents (compressed and uncompressed size, ratio)

-t, --test

test compressed file integrity

-v, --verbose

verbose mode

-1, --fast

compress faster

-9, --best

compress better

-h, --help

give this help

-V, --version

display version number

Examples

$ aws s3 cp s3://flow-logs/AWSLogs/.../x.log.gz - | zcat

read a delivered flow log file without saving it

Gotchas

• VPC flow logs delivered to S3 are .log.gz files: aws s3 cp s3://bucket/key.log.gz - | zcat | head.
• "gzip: stdin: not in gzip format" = the data was not compressed (or the download failed and you got an error text).