1 /* test.c - evaluate expression 2 * 3 * Copyright 2018 Rob Landley <rob@landley.net> 4 * 5 * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/test.html 6 7 USE_TEST(NEWTOY(test, 0, TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_NOHELP)) 8 9 config TEST 10 bool "test" 11 default y 12 help 13 usage: test [-bcdefghLPrSsuwx PATH] [-nz STRING] [-t FD] [X ?? Y] 14 15 Return true or false by performing tests. (With no arguments return false.) 16 17 --- Tests with a single argument (after the option): 18 PATH is/has: 19 -b block device -f regular file -p fifo -u setuid bit 20 -c char device -g setgid -r read bit -w write bit 21 -d directory -h symlink -S socket -x execute bit 22 -e exists -L symlink -s nonzero size 23 STRING is: 24 -n nonzero size -z zero size (STRING by itself implies -n) 25 FD (integer file descriptor) is: 26 -t a TTY 27 28 --- Tests with one argument on each side of an operator: 29 Two strings: 30 = are identical != differ 31 Two integers: 32 -eq equal -gt first > second -lt first < second 33 -ne not equal -ge first >= second -le first <= second 34 35 --- Modify or combine tests: 36 ! EXPR not (swap true/false) EXPR -a EXPR and (are both true) 37 ( EXPR ) evaluate this first EXPR -o EXPR or (is either true) 38 */ 39 40 #include "toys.h" 41 42 // Consume 3, 2, or 1 argument test, returning result and *count used. do_test(char ** args,int * count)43 int do_test(char **args, int *count) 44 { 45 char c, *s; 46 int i; 47 48 if (*count>=3) { 49 *count = 3; 50 char *s = args[1], *ss = "eqnegtgeltle"; 51 if (!strcmp(s, "=") || !strcmp(s, "==")) return !strcmp(args[0], args[2]); 52 if (!strcmp(s, "!=")) return strcmp(args[0], args[2]); 53 if (*s=='-' && strlen(s)==3 && (s = strstr(ss, s+1)) && !((i = s-ss)&1)) { 54 long long a = atolx(args[0]), b = atolx(args[2]); 55 56 if (!i) return a == b; 57 if (i==2) return a != b; 58 if (i==4) return a > b; 59 if (i==6) return a >= b; 60 if (i==8) return a < b; 61 if (i==10) return a<= b; 62 } 63 } 64 s = *args; 65 if (*count>=2 && *s == '-' && s[1] && !s[2]) { 66 *count = 2; 67 c = s[1]; 68 if (-1 != (i = stridx("hLbcdefgpSusxwr", c))) { 69 struct stat st; 70 71 // stat or lstat, then handle rwx and s 72 if (-1 == ((i<2) ? lstat : stat)(args[1], &st)) return 0; 73 if (i>=12) return !!(st.st_mode&(0x111<<(i-12))); 74 if (c == 's') return !!st.st_size; // otherwise 1<<32 == 0 75 76 // handle file type checking and SUID/SGID 77 if ((i = (unsigned short []){80,80,48,16,32,0,64,2,8,96,4}[i]<<9)>=4096) 78 return (st.st_mode&S_IFMT) == i; 79 else return (st.st_mode & i) == i; 80 } else if (c == 'z') return !*args[1]; 81 else if (c == 'n') return *args[1]; 82 else if (c == 't') return isatty(atolx(args[1])); 83 } 84 return *count = 0; 85 } 86 87 #define NOT 1 // Most recent test had an odd number of preceding ! 88 #define AND 2 // test before -a failed since -o or ( so force false 89 #define OR 4 // test before -o succeeded since ( so force true test_main(void)90 void test_main(void) 91 { 92 char *s; 93 int pos, paren, pstack, result = 0; 94 95 toys.exitval = 2; 96 if (!strcmp("[", toys.which->name)) 97 if (!toys.optc || strcmp("]", toys.optargs[--toys.optc])) 98 error_exit("Missing ']'"); 99 100 // loop through command line arguments 101 if (toys.optc) for (pos = paren = pstack = 0; ; pos++) { 102 int len = toys.optc-pos; 103 104 if (!toys.optargs[pos]) perror_exit("need arg @%d", pos); 105 106 // Evaluate next test 107 result = do_test(toys.optargs+pos, &len); 108 pos += len; 109 // Single argument could be ! ( or nonempty 110 if (!len) { 111 if (toys.optargs[pos+1]) { 112 if (!strcmp("!", toys.optargs[pos])) { 113 pstack ^= NOT; 114 continue; 115 } 116 if (!strcmp("(", toys.optargs[pos])) { 117 if (++paren>9) perror_exit("bad ("); 118 pstack <<= 3; 119 continue; 120 } 121 } 122 result = *toys.optargs[pos++]; 123 } 124 s = toys.optargs[pos]; 125 for (;;) { 126 127 // Handle pending ! -a -o (the else means -o beats -a) 128 if (pstack&NOT) result = !result; 129 pstack &= ~NOT; 130 if (pstack&OR) result = 1; 131 else if (pstack&AND) result = 0; 132 133 // Do it again for every ) 134 if (!paren || !s || strcmp(")", s)) break; 135 paren--; 136 pstack >>= 3; 137 s = toys.optargs[++pos]; 138 } 139 140 // Out of arguments? 141 if (!s) { 142 if (paren) perror_exit("need )"); 143 break; 144 } 145 146 // are we followed by -a or -o? 147 148 if (!strcmp("-a", s)) { 149 if (!result) pstack |= AND; 150 } else if (!strcmp("-o", s)) { 151 // -o flushes -a even if previous test was false 152 pstack &=~AND; 153 if (result) pstack |= OR; 154 } else error_exit("too many arguments"); 155 } 156 157 // Invert C logic to get shell logic 158 toys.exitval = !result; 159 } 160