When combining several input streams into a single file, so each part can be separated later, you want to separate the parts with a unique delimiter:
cat <<'THISISADELIMITER'
. . . .
. . . . stuff
. . . .
THISISADELIMITER
However, there is no guarantee that the delimiter you choose isn't already a line in the file. You could embed ends-of-file in the file, but reading past ends-of-file often causes strange behavior.
Therefore:
Prepend every line of the archive file with any character different from the first character of the delimiter; that is sufficient to make aliasing impossible:
#!/bin/sh
PATH=/bin:/usr/bin
echo '# To unbundle, sh this file'
for i
do
echo "echo $i 1>&2"
echo "sed 's/.//' >$i <<'//GO.SYSIN DD $i'"
sed 's/^/-/' $i
echo "//GO.SYSIN DD $i"
done
As a result, there is no aliasing; the archive file can have explicit delimiters that make it more self-documenting and easy to persue with
an editor.
Many thanks to
BrianKernighan, who is author of the
bundle script.
CategoryUnixShellPattern