Using imbedded commands inside expr(1)
William R. Pringle
wrp at PRC.Unisys.COM
Thu Nov 8 15:56:33 AEST 1990
In article <1462 at eastman.UUCP> gerwitz at kodak.com (Paul Gerwitz) writes:
>I seem to be having trouble using expr. The following dies:
>
> test=`expr `tail +3 file` + 1`
>
> Basically get a numeric value from a file and increment it, putting the
> result in a shell variable.
The backslash can be used to quote nested backward quotes (and other
strange characters):
test=`expr \`tail +3 file\` + 1`
Bill Pringle
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