1 files changed, 93 insertions, 0 deletions
diff --git a/src/execline/envfile.c b/src/execline/envfile.c
new file mode 100644
index 0000000..638b182
--- /dev/null
+++ b/src/execline/envfile.c
@@ -0,0 +1,93 @@
+/* ISC license. */
+
+#include <stdint.h>
+#include <string.h>
+
+#include <skalibs/types.h>
+#include <skalibs/buffer.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/env.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+
+#define USAGE "envfile file prog..."
+#define dieusage() strerr_dieusage(100, USAGE)
+#define dienomem() strerr_diefu1sys(111, "stralloc_catb")
+
+static inline uint8_t cclass (char c)
+{
+  switch (c)
+  {
+    case 0 : return 0 ;
+    case '#' : return 1 ;
+    case '\n' : return 2 ;
+    case '=' : return 3 ;
+    case ' ' :
+    case '\t' :
+    case '\f' :
+    case '\r' : return 4 ;
+    default : return 5 ;
+  }
+}
+
+static inline char next (char const *file, buffer *b)
+{
+  char c ;
+  ssize_t r = buffer_get(b, &c, 1) ;
+  if (r < 0) strerr_diefu2sys(111, "read from ", file) ;
+  if (!r) c = 0 ;
+  return c ;
+}
+
+static inline void parse_config (char const *file, buffer *b, stralloc *modif)
+{
+  static uint8_t const table[7][6] =
+  {
+    { 0x07, 0x01, 0x80, 0x08, 0x00, 0x22 },
+    { 0x07, 0x01, 0x80, 0x01, 0x01, 0x01 },
+    { 0x08, 0x08, 0x08, 0x24, 0x03, 0x22 },
+    { 0x08, 0x08, 0x08, 0x24, 0x03, 0x08 },
+    { 0x47, 0x41, 0xc0, 0x25, 0x04, 0x25 },
+    { 0x47, 0x41, 0xc0, 0x25, 0x46, 0x25 },
+    { 0x07, 0x01, 0x80, 0x08, 0x06, 0x08 }
+  } ;
+  unsigned int line = 1 ;
+  uint8_t state = 0 ;
+  while (state < 7)
+  {
+    char c = next(file, b) ;
+    uint8_t what = table[state][cclass(c)] ;
+    state = what & 0x0f ;
+    if (what & 0x20)
+      if (!stralloc_catb(modif, &c, 1)) dienomem() ;
+    if (what & 0x40)
+      if (!stralloc_0(modif)) dienomem() ;
+    if (what & 0x80) line++ ;
+  }
+  if (state > 7)
+  {
+    char fmt[UINT_FMT] ;
+    fmt[uint_fmt(fmt, line)] = 0 ;
+    strerr_dief4x(1, "syntax error line ", fmt, " while parsing ", file) ;
+  }
+}
+
+int main (int argc, char const *const *argv, char const *const *envp)
+{
+  stralloc modif = STRALLOC_ZERO ;
+  PROG = "envfile" ;
+  if (argc < 3) dieusage() ;
+  if (!strcmp(argv[1], "-"))
+    parse_config("standard input", buffer_0, &modif) ;
+  else
+  {
+    buffer b ;
+    char buf[BUFFER_INSIZE] ;
+    int fd = open_readb(argv[1]) ;
+    if (fd == -1) strerr_diefu2sys(111, "open ", argv[1]) ;
+    buffer_init(&b, &buffer_read, fd, buf, BUFFER_INSIZE) ;
+    parse_config(argv[1], &b, &modif) ;
+    fd_close(fd) ;
+  }
+  xpathexec_r(argv + 2, envp, env_len(envp), modif.s, modif.len) ;
+}