`env.nx` source

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1// env.nx -- parse .env / dotenv-style configuration files.
2//
3// The de facto standard for deployment config (Heroku, Vercel,
4// Docker Compose, direnv, 12-factor apps all use this format).
5// Line-oriented; each non-comment non-blank line is:
6//
7//   KEY=value
8//   KEY=\"value with spaces\"
9//   KEY='single-quoted'
10//   KEY=                    (explicit empty)
11//
12// Comments start with '#'.  Blank lines ignored.  Unquoted values
13// are trimmed of leading/trailing whitespace; quoted values are
14// taken verbatim between quote marks (no escape handling for
15// simplicity -- callers with \"dangerous\" values use JSON in the
16// .env + parse with json.nx).
17//
18// Keys must match [A-Za-z_][A-Za-z0-9_]* or the line is skipped.
19//
20// Used by: every Nishi service runtime for config, local dev
21// workflows, CI environment injection.
22//
23// Complements ini.nx (which has sections) + query.nx (URL encode)
24// by covering the linear-only case.
25//
26// Invariants:
27//   E1  Zero-alloc: offsets into caller's buffer.
28//   E2  Malformed lines silently skipped (caller logs if needed).
29//   E3  Duplicate keys both emitted; caller-supplied last-wins
30//       semantics if desired.
31//   E4  CRLF and bare LF line endings both accepted.
32
33import "syscalls.nx"
34
35const ENV_ERR_OVERFLOW: i64 = -1
36
37struct EnvEntry {
  key_off:   i64, key_len:   i64,
  val_off:   i64, val_len:   i64,
40}
41
42func env_is_key_start(b: i64) -> i64 {
  if b >= 0x41 {
      if b <= 0x5A { return 1 }
  }
  if b >= 0x61 {
      if b <= 0x7A { return 1 }
  }
  if b == 0x5F { return 1 }     // '_'
  return 0
51}
52
53func env_is_key_cont(b: i64) -> i64 {
  if env_is_key_start(b) == 1 { return 1 }
  if b >= 0x30 {
      if b <= 0x39 { return 1 }
  }
  return 0
59}
60
61func env_is_ws(b: i64) -> i64 {
  if b == 0x20 { return 1 }
  if b == 0x09 { return 1 }
  return 0
65}
66
67// Scan to end of line.  Returns offset of LF (or n if no LF).
68func env_eol(buf: *u8, n: i64, off: i64) -> i64 {
  var i: i64 = off
  while i < n {
      if buf[i] == 0x0A { return i }
      i = i + 1
  }
  return n
75}
76
77// Parse a .env file into caller's entry table.
78func env_parse(buf: *u8, n: i64,
             entries: *EnvEntry, cap: i64) -> i64 {
  var count: i64 = 0
  var line_start: i64 = 0
82
  while line_start < n {
      let line_end: i64 = env_eol(buf, n, line_start)
      // Trim CR before LF if CRLF.
      var eff_end: i64 = line_end
      if eff_end > line_start {
          if buf[eff_end - 1] == 0x0D { eff_end = eff_end - 1 }
      }
      // Skip leading whitespace.
      var i: i64 = line_start
      while i < eff_end {
          if env_is_ws(buf[i]) == 0 { break }
          i = i + 1
      }
      // Skip blank or comment lines.
      if i >= eff_end {
          line_start = line_end + 1
          continue
      }
      if buf[i] == 0x23 {
          line_start = line_end + 1
          continue
      }
      // Optional \"export \" prefix (bash-style dotenv).
      if i + 7 <= eff_end {
          if buf[i] == 0x65 {
              if buf[i + 1] == 0x78 {
                  if buf[i + 2] == 0x70 {
                      if buf[i + 3] == 0x6F {
                          if buf[i + 4] == 0x72 {
                              if buf[i + 5] == 0x74 {
                                  if buf[i + 6] == 0x20 {
                                      i = i + 7
                                      while i < eff_end {
                                          if env_is_ws(buf[i]) == 0 { break }
                                          i = i + 1
                                      }
                                  }
                              }
                          }
                      }
                  }
              }
          }
      }
127
      // Key must start with [A-Za-z_].
      if env_is_key_start(buf[i]) == 0 {
          line_start = line_end + 1
          continue
      }
      let key_start: i64 = i
      while i < eff_end {
          if env_is_key_cont(buf[i]) == 0 { break }
          i = i + 1
      }
      let key_end: i64 = i
139
      // Expect '='.
      if i >= eff_end {
          line_start = line_end + 1
          continue
      }
      if buf[i] != 0x3D {
          line_start = line_end + 1
          continue
      }
      i = i + 1
150
      // Value: handle quoted vs unquoted.
      var val_start: i64 = i
      var val_end: i64 = eff_end
      if i < eff_end {
          if buf[i] == 0x22 {
              // Double-quoted.
              val_start = i + 1
              var k: i64 = val_start
              while k < eff_end {
                  if buf[k] == 0x22 { break }
                  k = k + 1
              }
              val_end = k
          } else {
              if buf[i] == 0x27 {
                  // Single-quoted.
                  val_start = i + 1
                  var k: i64 = val_start
                  while k < eff_end {
                      if buf[k] == 0x27 { break }
                      k = k + 1
                  }
                  val_end = k
              } else {
                  // Unquoted: trim trailing whitespace.
                  var e: i64 = eff_end
                  while e > val_start {
                      if env_is_ws(buf[e - 1]) == 0 { break }
                      e = e - 1
                  }
                  val_end = e
              }
          }
      }
185
      if count >= cap { return ENV_ERR_OVERFLOW }
      let ent: *EnvEntry = entries + count * 32
      ent.key_off = key_start
      ent.key_len = key_end - key_start
      ent.val_off = val_start
      ent.val_len = val_end - val_start
      count = count + 1
193
      line_start = line_end + 1
  }
  return count
197}
198
199// Find by key.  Returns entry index or -1.
200func env_find(buf: *u8, entries: *EnvEntry, count: i64,
            key: *u8, key_len: i64) -> i64 {
  var i: i64 = 0
  while i < count {
      let e: *EnvEntry = entries + i * 32
      if e.key_len == key_len {
          var j: i64 = 0
          var ok: i64 = 1
          while j < key_len {
              if buf[e.key_off + j] != key[j] {
                  ok = 0
                  break
              }
              j = j + 1
          }
          if ok == 1 { return i }
      }
      i = i + 1
  }
  return -1
220}
221
222// Compile-only smoke.
223func main() -> i64 {
  let entries_raw: *u8 = sys_mmap(512)
  let entries: *EnvEntry = entries_raw as *EnvEntry
226
  let input: *u8 = "# Nishi deploy\nHOST=nishifamily.com\nPORT=443\nAPI_KEY=\"s e c r e t\"\nexport DB_URL=postgres://localhost/db\n"
  // Length: 15 + 22 + 9 + 21 + 36 = 103, plus trailing \n
  let n: i64 = env_parse(input, 104, entries, 16)
  if n != 4 { return 1 }
231
  // HOST key.
  let e0: *EnvEntry = entries
  if e0.key_len != 4 { return 2 }
  if e0.val_len != 15 { return 3 }        // "nishifamily.com"
  if input[e0.key_off] != 0x48 { return 4 }     // 'H'
237
  // API_KEY = "s e c r e t" (quoted, verbatim inside quotes)
  let e2: *EnvEntry = entries + 2 * 32
  if e2.val_len != 11 { return 5 }
241
  // Lookup.
  let idx: i64 = env_find(input, entries, n, "PORT", 4)
  if idx != 1 { return 6 }
  let e_port: *EnvEntry = entries + idx * 32
  if e_port.val_len != 3 { return 7 }
247
  // export DB_URL= prefix stripped.
  let idx_db: i64 = env_find(input, entries, n, "DB_URL", 6)
  if idx_db != 3 { return 8 }
251
  return 0
253}
env.nx source

`env.nx` source
