From 64d63f8fd06e5370694f760093c69cdc69652447 Mon Sep 17 00:00:00 2001 From: Laurent Bercot Date: Wed, 11 Aug 2021 01:34:55 +0000 Subject: Add case (yet untested) Signed-off-by: Laurent Bercot --- NEWS | 1 + doc/case.html | 93 ++++++++++++++++++++++++++++++++++ doc/index.html | 1 + doc/trap.html | 6 ++- package/deps.mak | 3 ++ package/modes | 13 ++--- package/targets.mak | 1 + src/execline/case.c | 123 +++++++++++++++++++++++++++++++++++++++++++++ src/execline/deps-exe/case | 2 + 9 files changed, 235 insertions(+), 8 deletions(-) create mode 100644 doc/case.html create mode 100644 src/execline/case.c create mode 100644 src/execline/deps-exe/case diff --git a/NEWS b/NEWS index 7941c37..c1f0a36 100644 --- a/NEWS +++ b/NEWS @@ -4,6 +4,7 @@ In 2.8.1.0 ---------- - Adaptation to skalibs-2.11.0.0. + - New binary: case. In 2.8.0.1 diff --git a/doc/case.html b/doc/case.html new file mode 100644 index 0000000..5340c07 --- /dev/null +++ b/doc/case.html @@ -0,0 +1,93 @@ + + + + + + execline: the case command + + + + + + +

+execline
+Software
+skarnet.org +

+ +

The `case` program

+ +

+case compares a value against a series of regular expressions, +and executes into a program depending on the first expression the value +matches. +

+ +

Interface

+ +

+ In an execlineb script: +

+ +

+     case [ -E | -e | -i | -n ] value
+     {
+       [ regex { prog... } ]
+       [ regex { prog... } ]
+       ...
+     }
+     progdefault...
+

+ +

case reads an argument value and a sequence of +directives in a block.
Each directive is a regular expression followed by a block.
case matches value against the regular expressions +in the order they are given.
As soon as value matches a regex, case +executes into the prog... command line that immediately follows +the matched regex.
If value matches no regex, case +eventually execs into progdefault....

+ +

Options

+ +

-e : Interpret the regex words as +basic +regular expressions.
-E : Interpret the regex words as +extended +regular expressions. This is the default.
-i : Perform case-insensitive matches.
-n : Do not transmit the matching expression and +subexpressions to prog... via the environment. This is the default.
-N : Make the matching expression and +subexpressions available to prog's environment.

+ +

Subexpression matching

+ +

+ If the -N option has been given, and value matches a regex, +then case will run prog with a modified environment: +

+ +

The 0 variable will contain the regex that value matched.
The # variable will contain the number of subexpressions in regex.
For every integer i between 1 and the number of subexpressions (included), the +variable i contains the part of value that matched the ith subexpression +in regex.

+ +

+ To retrieve that information into your command line in an execline script, you can use the +elgetpositionals program. +

+ + + diff --git a/doc/index.html b/doc/index.html index 035e0eb..7dae446 100644 --- a/doc/index.html +++ b/doc/index.html @@ -167,6 +167,7 @@ to your installation: the shebang lines for your system might be something like

The foreground program
The background program
The case program
The if program
The ifelse program
The ifte program

execline: the trap command

The `trap` program

trap traps signals and runs a variety of commands according to the signals it catches. +

Interface

+#include + +#include +#include +#include +#include +#include + +#include + +#define USAGE "case [ -e | -E ] [ -n | -N ] [ -i ] value { re1 { prog1... } re2 { prog2... } ... } progdefault... " +#define dieusage() strerr_dieusage(100, USAGE) + +static void execit (char const *const *argv, char const *expr, char const *s, regmatch_t const *pmatch, size_t nsub, int flagnosub) gccattr_noreturn ; +static void execit (char const *const *argv, char const *expr, char const *s, regmatch_t const *pmatch, size_t nsub, int flagnosub) +{ + if (flagnosub) xexec0(argv) ; + else + { + size_t exprlen = strlen(expr) ; + size_t fmtlen = exprlen + 6 ; + for (size_t i = 0 ; i < nsub ; i++) + fmtlen += uint_fmt(0, i+1) + 2 + pmatch[i].rm_eo - pmatch[i].rm_so ; + { + size_t m = 0 ; + char fmt[fmtlen] ; + fmt[m++] = '#' ; fmt[m++] = '=' ; + m += uint_fmt(fmt + m, nsub) ; + fmt[m++] = 0 ; + fmt[m++] = '0' ; fmt[m++] = '=' ; + memcpy(fmt + m, expr, exprlen + 1) ; m += exprlen + 1 ; + for (size_t i = 0 ; i < nsub ; i++) + { + m += uint_fmt(fmt + m, i+1) ; + fmt[m++] = '=' ; + memcpy(fmt + m, s + pmatch[i].rm_so, pmatch[i].rm_eo - pmatch[i].rm_so) ; + fmt[m++] = 0 ; + } + xmexec0_n(argv, fmt, fmtlen, 2 + nsub) ; + } + } +} + +int main (int argc, char const **argv, char const *const *envp) +{ + int flagextended = 1 ; + int flagicase = 0 ; + int flagnosub = 1 ; + int argc1 ; + unsigned int i = 0 ; + char const *s ; + PROG = "case" ; + { + subgetopt l = SUBGETOPT_ZERO ; + for (;;) + { + int opt = subgetopt_r(argc, argv, "eEnNi", &l) ; + if (opt == -1) break ; + switch (opt) + { + case 'e' : flagextended = 0 ; break ; + case 'E' : flagextended = 1 ; break ; + case 'N' : flagnosub = 0 ; break ; + case 'n' : flagnosub = 1 ; break ; + case 'i' : flagicase = 1 ; break ; + default : dieusage() ; + } + } + argc -= l.ind ; argv += l.ind ; + } + if (argc-- < 2) dieusage() ; + s = *argv++ ; + + argc1 = el_semicolon(argv) ; + if (argc1 >= argc) strerr_dief1x(100, "unterminated case block") ; + + while (i < argc1) + { + char const *expr = argv[i++] ; + int argc2 ; + regex_t re ; + if (i == argc1) strerr_dief1x(100, "malformed case block") ; + argc2 = el_semicolon(argv + i) ; + if (i + argc2 >= argc1) strerr_dief1x(100, "unterminated regex block") ; + { + int r ; + size_t len = strlen(expr) ; + char tmp[len+3] ; + tmp[0] = '^' ; + memcpy(tmp + 1, expr, len) ; + tmp[1+len] = '$' ; + tmp[2+len] = 0 ; + r = regcomp(&re, tmp, (flagextended ? REG_EXTENDED : 0) | (flagicase ? REG_ICASE : 0) | (flagnosub ? REG_NOSUB : 0) | REG_NEWLINE) ; + if (r) + { + char buf[256] ; + regerror(r, &re, buf, 256) ; + strerr_diefu4x(r == REG_ESPACE ? 111 : 100, "regcomp \"^", argv[i], "$\": ", buf) ; + } + } + { + regmatch_t pmatch[re.re_nsub && !flagnosub ? re.re_nsub : 1] ; + int r = regexec(&re, s, re.re_nsub, pmatch, 0) ; + if (!r) + { + argv[i + argc2] = 0 ; + execit(argv + i, expr, s, pmatch, flagnosub ? 0 : re.re_nsub, flagnosub) ; + } + if (r != REG_NOMATCH) + { + char buf[256] ; + regerror(r, &re, buf, 256) ; + strerr_diefu6x(111, "match string \"", s, "\" against regex \"", expr, "\": ", buf) ; + } + } + regfree(&re) ; + i += argc2 + 1 ; + } + xexec0(argv + argc1 + 1) ; +} diff --git a/src/execline/deps-exe/case b/src/execline/deps-exe/case new file mode 100644 index 0000000..97021b5 --- /dev/null +++ b/src/execline/deps-exe/case @@ -0,0 +1,2 @@ +${LIBEXECLINE} +-lskarnet -- cgit v1.2.3

The case program

Interface

Options

Subexpression matching

The trap program

Interface

The `case` program

The `trap` program