michael wrote: > echo Usage\: $0 [string file] > echo To loop until \$string found in \$file
Better to quote the entire line. Because [...] is special to the
shell the [string file] will try to file glob match against files in
the local directory. It is unlikely to match in this case but it will
slow down and on a networked directory may be very slow and in other
cases it might actually match creating a directory data dependent
failure mode. And besides, ':' doesn't need to be quoted there.
Also the synopsis line would normally be written without requiring the
user to know that $variable is a variable. They don't need to know
that the implementation is a shell script. It might be C or Ruby.
echo "Usage: $0 [STRING FILE]"
echo "To loop until STRING found in FILE."
> while [[ `grep -e "${STRING}" ${FILE} |wc -l` -lt 1 ]];do
Using grep piped to wc -l is the same as using grep -c. In many cases
the savings in character I/O of piping large amounts of output from
one command to the next can be very large. And it is just a good
idea. And since you are using the new style [[...]] already you
might as well use the new style $(...) with the more regular and
easier to understand quoting rules.
while [[ $(grep -c -e "${STRING}" ${FILE}) -lt 1 ]];do
Bob
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