The C shell has two
that, when set, will help you follow the
convoluted trail of variable and metacharacter expansion.
This will echo every command line before shell variables
have been evaluated:
This command will display each line after the variables and
metacharacters have been substituted:
If you wish to turn the variables off, use
The Bourne shell syntax is different.
To turn on the verbose flag, use:
turns on the echo flag.
You can also type them together:
If your version of UNIX
scripts that start with
here's a convenient way to turn these variables on from
the first line of a script:
It is not necessary to modify the program.
You can enable variable tracing in Bourne shell scripts by typing the
shell name and options on the command line:
Not all Bourne shells let you turn these variables off.
If yours does, you can do it by using a plus sign instead of a minus sign: