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Operating Systems OS X (Apple) Generate a random number in a fully POSIX compliant shell, 'dash'... Post 303043172 by wisecracker on Monday 20th of January 2020 04:48:24 PM
Old 01-20-2020
Hi MadeInGermany...
Although there is a workaround this is an edge case:
Code:
#!/usr/local/bin/dash
# lead_zeros.sh

# This is a gotcha...
# There will always be 6 zeros sooner or later, 000000.
 
# Only the last 6 digits are really needed... 
TEST_VAL=0.000000
TEST_NUM=123

num=${TEST_VAL#??}
echo "${num}"
lz=${num%%[1-9]*}
echo "${lz}"
TEST_VAL=${num#$lz}

echo "Test value = ${TEST_VAL}..."

TEST_VAL=$(( TEST_VAL * TEST_NUM ))

echo "Required integer = ${TEST_VAL}..."

Results:
Code:
Last login: Mon Jan 20 21:18:42 on ttys000
AMIGA:amiga~> cd Desktop/Code/Shell
AMIGA:amiga~/Desktop/Code/Shell> chmod 755 lead_zeros.sh
AMIGA:amiga~/Desktop/Code/Shell> ./lead_zeros.sh
000000
000000
Test value = ...
./lead_zeros.sh: 19: ./lead_zeros.sh: Illegal number: 
AMIGA:amiga~/Desktop/Code/Shell> _

EDIT:
This is a workaround...
TEST_VAL=$(( (${TEST_VAL} + 0 ) * TEST_NUM ))

Last edited by wisecracker; 01-20-2020 at 06:46 PM.. Reason: See EDIT:
 

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echo(1) 						      General Commands Manual							   echo(1)

NAME
echo - echo (print) arguments SYNOPSIS
[arg] ... DESCRIPTION
writes its arguments separated by blanks and terminated by a new-line on the standard output. It also understands C-like escape conven- tions; beware of conflicts with the shell's use of write an alert character backspace print line without appending a new-line form-feed new-line carriage return tab vertical tab backslash the 8-bit character whose ASCII code is the 1-, 2-, 3- or 4-digit octal number n, whose first character must be a zero. write an 8-bit value that is the zero-, one-, two- or three-digit octal number num is useful for producing diagnostics in command files and for sending known data into a pipe. Notes Berkeley differs from this implementation. The former does not implement the backslash escapes. However, the semantics of the escape can be obtained by using the option. The echo command implemented as a built-in function of follows the Berkeley semantics (see csh(1)). EXTERNAL INFLUENCES
Environment Variables determines the interpretation of arg as single and/or multi-byte characters. If is not specified in the environment or is set to the empty string, the value of is used as a default for each unspecified or empty vari- able. If is not specified or is set to the empty string, a default of "C" (see lang(5)) is used instead of If any internationalization variable contains an invalid setting, behaves as if all internationalization variables are set to "C". See environ(5). International Code Set Support Single- and multi-byte character code sets are supported. AUTHOR
was developed by OSF and HP. SEE ALSO
sh(1). BUGS
No characters are printed after the first This is not normally a problem. STANDARDS CONFORMANCE
echo(1)
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