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Top Forums UNIX for Dummies Questions & Answers What's wrong with this line: if ${TEST:?} ; then echo empty; fi Post 302169936 by zazzybob on Saturday 23rd of February 2008 05:14:55 AM
Old 02-23-2008
Code:
$ cat > foo.ksh
#!/bin/ksh
TEST=
FOO=${TEST:?empty}
$ chmod +x ./foo.ksh$ ./foo.ksh
./foo.ksh: line 3: TEST: empty
$ sed 's/^TEST=/TEST=something/' foo.ksh > foo2.ksh
$ chmod +x ./foo2.ksh
$ ./foo2.ksh
$

No need for the conditional structure, a simple variable assignment will do it.

Cheers,
ZB
 

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TEST(1) 						      General Commands Manual							   TEST(1)

NAME
test - condition command SYNOPSIS
test expr DESCRIPTION
test evaluates the expression expr, and if its value is true then returns zero exit status; otherwise, a non zero exit status is returned. test returns a non zero exit if there are no arguments. The following primitives are used to construct expr. -r file true if the file exists and is readable. -w file true if the file exists and is writable. -f file true if the file exists and is not a directory. -d file true if the file exists and is a directory. -s file true if the file exists and has a size greater than zero. -t [ fildes ] true if the open file whose file descriptor number is fildes (1 by default) is associated with a terminal device. -z s1 true if the length of string s1 is zero. -n s1 true if the length of the string s1 is nonzero. s1 = s2 true if the strings s1 and s2 are equal. s1 != s2 true if the strings s1 and s2 are not equal. s1 true if s1 is not the null string. n1 -eq n2 true if the integers n1 and n2 are algebraically equal. Any of the comparisons -ne, -gt, -ge, -lt, or -le may be used in place of -eq. These primaries may be combined with the following operators: ! unary negation operator -a binary and operator -o binary or operator ( expr ) parentheses for grouping. -a has higher precedence than -o. Notice that all the operators and flags are separate arguments to test. Notice also that parentheses are meaningful to the Shell and must be escaped. SEE ALSO
sh(1), find(1) TEST(1)
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