postgres

History

Tom Lane f833c847b8 Allow psql variable substitution to occur in backtick command strings. Previously, text between backquotes in a psql metacommand's arguments was always passed to the shell literally. That considerably hobbles the usefulness of the feature for scripting, so we'd foreseen for a long time that we'd someday want to allow substitution of psql variables into the shell command. IMO the addition of \if metacommands has brought us to that point, since \if can greatly benefit from some sort of client-side expression evaluation capability, and psql itself is not going to grow any such thing in time for v10. Hence, this patch. It allows :VARIABLE to be replaced by the exact contents of the named variable, while :'VARIABLE' is replaced by the variable's contents suitably quoted to become a single shell-command argument. (The quoting rules for that are different from those for SQL literals, so this is a bit of an abuse of the :'VARIABLE' notation, but I doubt anyone will be confused.) As with other situations in psql, no substitution occurs if the word following a colon is not a known variable name. That limits the risk of compatibility problems for existing psql scripts; but the risk isn't zero, so this needs to be called out in the v10 release notes. Discussion: https://postgr.es/m/9561.1490895211@sss.pgh.pa.us		9 years ago
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.gitignore	Move psql's psqlscan.l into src/fe_utils.	10 years ago
Makefile	Suppress "unused variable" warnings with older versions of flex.	9 years ago
mbprint.c	Update copyright via script for 2017	9 years ago
print.c	Remove useless duplicate inclusions of system header files.	9 years ago
psqlscan.l	Allow psql variable substitution to occur in backtick command strings.	9 years ago
simple_list.c	Update copyright via script for 2017	9 years ago
string_utils.c	Allow psql variable substitution to occur in backtick command strings.	9 years ago