Fresh implementation of test.c.

1 files changed, 159 insertions, 0 deletions

diff --git a/toys/posix/test.c b/toys/posix/test.c
new file mode 100644
index 00000000..052b8deb
--- /dev/null
+++ b/toys/posix/test.c
@@ -0,0 +1,159 @@
+/* test.c - evaluate expression
+ *
+ * Copyright 2018 Rob Landley <rob@landley.net>
+ *
+ * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/test.html
+
+USE_TEST(NEWTOY(test, 0, TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_NOHELP))
+
+config TEST
+  bool "test"
+  default y
+  help
+    usage: test [-bcdefghLPrSsuwx PATH] [-nz STRING] [-t FD] [X ?? Y]
+
+    Return true or false by performing tests. (With no arguments return false.)
+
+    --- Tests with a single argument (after the option):
+    PATH is/has:
+      -b  block device   -f  regular file   -p  fifo           -u  setuid bit
+      -c  char device    -g  setgid         -r  read bit       -w  write bit
+      -d  directory      -h  symlink        -S  socket         -x  execute bit
+      -e  exists         -L  symlink        -s  nonzero size
+    STRING is:
+      -n  nonzero size   -z  zero size      (STRING by itself implies -n)
+    FD (integer file descriptor) is:
+      -t  a TTY
+
+    --- Tests with one argument on each side of an operator:
+    Two strings:
+      =  are identical   !=  differ
+    Two integers:
+      -eq  equal         -gt  first > second    -lt  first < second
+      -ne  not equal     -ge  first >= second   -le  first <= second
+
+    --- Modify or combine tests:
+      ! EXPR     not (swap true/false)   EXPR -a EXPR    and (are both true)
+      ( EXPR )   evaluate this first     EXPR -o EXPR    or (is either true)
+*/
+
+#include "toys.h"
+
+// Consume 3, 2, or 1 argument test, returning result and *count used.
+int do_test(char **args, int *count)
+{
+  char c, *s;
+  int i;
+
+  if (*count>=3) {
+    *count = 3;
+    char *s = args[1], *ss = "eqnegtgeltle";
+    if (!strcmp(s, "=") || !strcmp(s, "==")) return !strcmp(args[0], args[2]);
+    if (!strcmp(s, "!=")) return strcmp(args[0], args[2]);
+    if (*s=='-' && strlen(s)==3 && (s = strstr(ss, s+1)) && !((i = s-ss)&1)) {
+      long long a = atolx(args[0]), b = atolx(args[2]);
+
+      if (!i) return a == b;
+      if (i==2) return a != b;
+      if (i==4) return a > b;
+      if (i==6) return a >= b;
+      if (i==8) return a < b;
+      if (i==10) return a<= b;
+    }
+  }
+  s = *args;
+  if (*count>=2 && *s == '-' && s[1] && !s[2]) {
+    *count = 2;
+    c = s[1];
+    if (-1 != (i = stridx("hLbcdefgpSusxwr", c))) {
+      struct stat st;
+
+      // stat or lstat, then handle rwx and s
+      if (-1 == ((i<2) ? lstat : stat)(args[1], &st)) return 0;
+      if (i>=12) return !!(st.st_mode&(0x111<<(i-12)));
+      if (c == 's') return !!st.st_size; // otherwise 1<<32 == 0
+
+      // handle file type checking and SUID/SGID
+      if ((i = (unsigned short []){80,80,48,16,32,0,64,2,8,96,4}[i]<<9)>=4096)
+        return (st.st_mode&S_IFMT) == i;
+      else return (st.st_mode & i) == i;
+    } else if (c == 'z') return !*args[1];
+    else if (c == 'n') return *args[1];
+    else if (c == 't') return isatty(atolx(args[1]));
+  }
+  return *count = 0;
+}
+
+#define NOT 1  // Most recent test had an odd number of preceding !
+#define AND 2  // test before -a failed since -o or ( so force false
+#define OR  4  // test before -o succeeded since ( so force true
+void test_main(void)
+{
+  char *s;
+  int pos, paren, pstack, result = 0;
+
+  toys.exitval = 2;
+  if (!strcmp("[", toys.which->name))
+    if (!toys.optc || strcmp("]", toys.optargs[--toys.optc]))
+      error_exit("Missing ']'");
+
+  // loop through command line arguments
+  if (toys.optc) for (pos = paren = pstack = 0; ; pos++) {
+    int len = toys.optc-pos;
+
+    if (!toys.optargs[pos]) perror_exit("need arg @%d", pos);
+
+    // Evaluate next test
+    result = do_test(toys.optargs+pos, &len);
+    pos += len;
+    // Single argument could be ! ( or nonempty
+    if (!len) {
+      if (toys.optargs[pos+1]) {
+        if (!strcmp("!", toys.optargs[pos])) {
+          pstack ^= NOT;
+          continue;
+        }
+        if (!strcmp("(", toys.optargs[pos])) {
+          if (++paren>9) perror_exit("bad (");
+          pstack <<= 3;
+          continue;
+        }
+      }
+      result = *toys.optargs[pos++];
+    }
+    s = toys.optargs[pos];
+    for (;;) {
+
+      // Handle pending ! -a -o (the else means -o beats -a)
+      if (pstack&NOT) result = !result;
+      pstack &= ~NOT;
+      if (pstack&OR) result = 1;
+      else if (pstack&AND) result = 0;
+
+      // Do it again for every )
+      if (!paren || !s || strcmp(")", s)) break;
+      paren--;
+      pstack >>= 3;
+      s = toys.optargs[++pos];
+    }
+
+    // Out of arguments?
+    if (!s) {
+      if (paren) perror_exit("need )");
+      break;
+    }
+
+    // are we followed by -a or -o?
+
+    if (!strcmp("-a", s)) {
+      if (!result) pstack |= AND;
+    } else if (!strcmp("-o", s)) {
+      // -o flushes -a even if previous test was false
+      pstack &=~AND;
+      if (result) pstack |= OR;
+    } else error_exit("too many arguments");
+  }
+
+  // Invert C logic to get shell logic
+  toys.exitval = !result;
+}