Add case (yet untested)

Signed-off-by: Laurent Bercot <ska@appnovation.com>

2 files changed, 125 insertions, 0 deletions

diff --git a/src/execline/case.c b/src/execline/case.c
new file mode 100644
index 0000000..8fdf21e
--- /dev/null
+++ b/src/execline/case.c
@@ -0,0 +1,123 @@
+/* ISC license. */
+
+#include <string.h>
+#include <regex.h>
+
+#include <skalibs/gccattributes.h>
+#include <skalibs/types.h>
+#include <skalibs/sgetopt.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/exec.h>
+
+#include <execline/execline.h>
+
+#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