share-sum.md

[[share build dependencies]]

Compute the checksum of the given dependency.

Code

share-sum:debug: set -x

If the file is a variable ($var), echo the current value of the variable, and take its checksum with [[md5sum]].

share-sum: if echo "$*" | grep '^\$' >/dev/null 2>&1; then
share-sum:     eval "echo $*" | md5sum
share-sum:     exit 0
share-sum: fi

If the file is a command (has a space), catenate the standard output of the command, and take its checksum with [[md5sum]].

share-sum: if echo "$*" | grep '␣' >/dev/null 2>&1; then
share-sum:     eval $(echo $* | sed 's,␣, ,g') | md5sum
share-sum:     exit 0
share-sum: fi

If we are given a target that is a directory, then we want to calculate the checksum of the directory based on the long list of files in the directory. This will detect date changes, size changes, and ownership and permissions changes of the files, as well as added, renamed, or removed files, without calculating checksums of each of the files. #testing

share-sum: if test -d "$*"; then
share-sum:     cd "$*"
share-sum:     ls -l | md5sum
share-sum:     exit 0
share-sum: fi

Just take the checksum if a the file is readable.

share-sum: if test -r "$*"; then
share-sum:     cat "$*" | md5sum
share-sum:     exit 0
share-sum: fi

Otherwise, keep the checksum unknown.

share-sum: echo 0
share-sum: exit 0

Usage

lit 'lit=share-sum.md' 'file=share-sum'
lit 'lit=share-sum.md' 'file=share-sum' 'variant=debug'

share sum polylingual_hello.md

share sum '$PATH'

share sum always

share sum 'hello.o.env'
cd hello.o.env; host ls -l | host md5sum

share sum gcc --version
share sum gcc␣--version