initial commit: rc for execline-2.0.0.0

1 files changed, 179 insertions, 0 deletions

diff --git a/src/libexecline/el_substitute.c b/src/libexecline/el_substitute.c
new file mode 100644
index 0000000..a94c16d
--- /dev/null
+++ b/src/libexecline/el_substitute.c
@@ -0,0 +1,179 @@
+/* ISC license. */
+
+#include <skalibs/bytestr.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/genalloc.h>
+#include <execline/execline.h>
+
+typedef struct elsubsu_s elsubsu_t, *elsubsu_t_ref ;
+struct elsubsu_s
+{
+  elsubst_t const *subst ;
+  unsigned int pos ;
+} ;
+
+typedef struct subsuinfo_s subsuinfo_t, *subsuinfo_t_ref ;
+struct subsuinfo_s
+{
+  stralloc dst ;
+  stralloc sa ;
+  genalloc list ; /* array of elsubsu_t */
+  char const *values ;
+} ;
+
+#define SUBSUINFO_ZERO { .dst = STRALLOC_ZERO, .sa = STRALLOC_ZERO, .list = GENALLOC_ZERO, .values = 0 }
+
+#define TEST 0x80
+#define MARK 0x40
+#define KEEPESC 0x20
+#define INCRESC 0x10
+
+#define STATE 0x07
+#define INWORD 0x00
+#define INDOLL 0x01
+#define INDBR 0x02
+#define INVAR 0x03
+#define INVARBR 0x04
+#define ACCEPT 0x05
+
+static int parseword (stralloc *sa, genalloc *list, char const *s, char const *vars, elsubst_t const *substs, unsigned int nsubst)
+{
+  static char const class[5] = "\0\\${}" ;
+  static unsigned char const table[6][5] =
+  {
+    { ACCEPT, ACCEPT, ACCEPT, ACCEPT | TEST, ACCEPT },
+    { INWORD | KEEPESC | INCRESC, INWORD | INCRESC, INWORD | INCRESC, INWORD | TEST | INCRESC, INWORD | INCRESC },
+    { INDOLL | KEEPESC, INDOLL, INDOLL, INDOLL | TEST, INDOLL },
+    { INWORD, INDBR | KEEPESC, INWORD, INWORD | TEST, INWORD },
+    { INWORD, INWORD, INWORD, INWORD | TEST, INWORD | TEST },
+    { INWORD, INVAR | MARK | KEEPESC, INVARBR | MARK | KEEPESC, INVAR | KEEPESC, INVARBR | KEEPESC }
+  } ;
+
+  unsigned int mark = 0, pos = 0, offset = 0, esc = 0, salen = sa->len, listlen = genalloc_len(elsubsu_t, list) ;
+  unsigned char state = INWORD ;
+
+  while (state != ACCEPT)
+  {
+    int nopush = 0 ;
+    unsigned char c = table[byte_chr(class, 5, s[pos])][state] ;
+
+    if (c & TEST)
+    {
+      unsigned int supp = (state == INVARBR) ;
+      unsigned int i = 0 ;
+      for (; i < nsubst ; i++)
+      {
+        if (!str_diffn(vars + substs[i].var, s + mark, pos - mark) && !vars[substs[i].var + pos - mark])
+        {
+          sa->len -= esc >> 1 ; offset += esc >> 1 ;
+          if (esc & 1)
+          {
+            byte_copy(sa->s + mark - offset - 2 - supp, pos - mark + 1 + supp, sa->s + mark - offset + (esc>>1) - 1 - supp) ;
+            sa->len-- ; offset++ ;
+          }
+          else
+          {
+            elsubsu_t cur ;
+            cur.subst = substs + i ;
+            cur.pos = mark - offset - 1 - supp ;
+            if (!genalloc_append(elsubsu_t, list, &cur)) goto err ;
+            offset += sa->len - cur.pos ;
+            sa->len = cur.pos ;
+            if (supp) nopush = 1 ;
+          }
+          break ;
+        }
+      }
+    }
+    if (nopush) offset++ ;
+    else if (!stralloc_catb(sa, s+pos, 1)) goto err ;
+    if (c & MARK) mark = pos ;
+    if (!(c & KEEPESC)) esc = 0 ;
+    if (c & INCRESC) esc++ ;
+    state = c & STATE ; pos++ ;
+  }
+  sa->len-- ;
+  return (int)pos ;
+
+err:
+  sa->len = salen ;
+  list->len = listlen ;
+  return -1 ;
+}
+
+static int substword (subsuinfo_t *info, unsigned int wordstart, unsigned int wordlen, unsigned int n, unsigned int offset)
+{
+  if (n < genalloc_len(elsubsu_t, &info->list))
+  {
+    elsubsu_t *list = genalloc_s(elsubsu_t, &info->list) ;
+    char const *p = info->values + list[n].subst->value ;
+    unsigned int l = list[n].pos + offset ;
+    unsigned int dstbase = info->dst.len ;
+    unsigned int sabase = info->sa.len ;
+    unsigned int i = 0 ;
+    int nc = 0 ;
+    if (!stralloc_readyplus(&info->sa, l)) return -1 ;
+    stralloc_catb(&info->sa, info->sa.s + wordstart, l) ;
+    for ( ; i < list[n].subst->n ; i++)
+    {
+      int r ;
+      unsigned int plen = str_len(p) ;
+      info->sa.len = sabase + l ;
+      if (!stralloc_readyplus(&info->sa, plen + wordlen - l)) goto err ;
+      stralloc_catb(&info->sa, p, plen) ;
+      stralloc_catb(&info->sa, info->sa.s + wordstart + l, wordlen - l) ;
+      r = substword(info, sabase, info->sa.len - sabase, n+1, offset + plen) ;
+      if (r < 0) goto err ;
+      nc += r ;
+      p += plen+1 ;
+    }
+    return nc ;
+   err:
+    info->sa.len = sabase ;
+    info->dst.len = dstbase ;
+    return -1 ;
+  }
+  else
+  {
+    if (!stralloc_readyplus(&info->dst, wordlen+1)) return -1 ;
+    stralloc_catb(&info->dst, info->sa.s + wordstart, wordlen) ;
+    stralloc_0(&info->dst) ;
+    return 1 ;
+  }
+}
+
+int el_substitute (stralloc *dst, char const *src, unsigned int len, char const *vars, char const *values, elsubst_t const *substs, unsigned int nsubst)
+{
+  subsuinfo_t info = SUBSUINFO_ZERO ;
+  unsigned int nc = 0 ;
+  unsigned int i = 0 ;
+  unsigned int dstbase = dst->len ;
+  int wasnull = !dst->s ;
+  info.dst = *dst ;
+  info.values = values ;
+
+  while (i < len)
+  {
+    int r ;
+    genalloc_setlen(elsubsu_t, &info.list, 0) ;
+    info.sa.len = 0 ;
+    r = parseword(&info.sa, &info.list, src + i, vars, substs, nsubst) ;
+    if (r < 0) goto err ;
+    i += r ;
+    r = substword(&info, 0, info.sa.len, 0, 0) ;
+    if (r < 0) goto err ;
+    nc += r ;
+  }
+  genalloc_free(elsubsu_t, &info.list) ;
+  stralloc_free(&info.sa) ;
+  if (!wasnull) stralloc_free(dst) ;
+  *dst = info.dst ;
+  return (int)nc ;
+
+err :
+  genalloc_free(elsubsu_t, &info.list) ;
+  stralloc_free(&info.sa) ;
+  if (wasnull) stralloc_free(&info.dst) ; else info.dst.len = dstbase ;
+  *dst = info.dst ;
+  return -1 ;
+}