On 6/29/25 10:13 AM, Stan Marsh wrote:
I always thought the "colon-free" versions of the P.E. was a bash-ism, but experimentation shows that it works in "dash" as well. And "man dash" contains the following text:In the parameter expansions shown previously, use of the colon in the format re- sults in a test for a parameter that is unset or null; omission of the colon re- sults in a test for a parameter that is only unset. So, is this POSIX, or just a dash-extension?
The POSIX standard is freely available https://pubs.opengroup.org/onlinepubs/9799919799/nfindex.html and would answer your question. https://pubs.opengroup.org/onlinepubs/9799919799/utilities/V3_chap02.html#tag_19_06_02 -- ``The lyf so short, the craft so long to lerne.'' - Chaucer ``Ars longa, vita brevis'' - Hippocrates Chet Ramey, UTech, CWRU c...@case.edu http://tiswww.cwru.edu/~chet/
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