From a9baddd7d07b9fe15e212985a808a79773ec72e4 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sat, 19 Mar 2011 22:26:06 -0400 Subject: initial check-in, taken from old libc svn repo with significant additions --- snprintf.c | 120 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+) create mode 100644 snprintf.c (limited to 'snprintf.c') diff --git a/snprintf.c b/snprintf.c new file mode 100644 index 0000000..1e563e5 --- /dev/null +++ b/snprintf.c @@ -0,0 +1,120 @@ +#include +#include +#include +#include +#include + +#define TEST(r, f, x, m) ( \ +((r) = (f)) == (x) || \ +(printf(__FILE__ ":%d: %s failed (" m ")\n", __LINE__, #f, r, x), err++, 0) ) + +#define TEST_S(s, x, m) ( \ +!strcmp((s),(x)) || \ +(printf(__FILE__ ":%d: [%s] != [%s] (%s)\n", __LINE__, s, x, m), err++, 0) ) + +static const struct { + const char *fmt; + int i; + const char *expect; +} int_tests[] = { + /* width, precision, alignment */ + { "%04d", 12, "0012" }, + { "%.3d", 12, "012" }, + { "%3d", 12, " 12" }, + { "%-3d", 12, "12 " }, + { "%+3d", 12, "+12" }, + { "%+-5d", 12, "+12 " }, + { "%+- 5d", 12, "+12 " }, + { "%- 5d", 12, " 12 " }, + { "% d", 12, " 12" }, + { "%0-5d", 12, "12 " }, + { "%-05d", 12, "12 " }, + + /* ...explicit precision of 0 shall be no characters. */ + { "%.0d", 0, "" }, + { "%.0o", 0, "" }, + { "%#.0d", 0, "" }, + { "%#.0o", 0, "" }, + { "%#.0x", 0, "" }, + + /* hex: test alt form and case */ + { "%x", 63, "3f" }, + { "%#x", 63, "0x3f" }, + { "%X", 63, "3F" }, + + /* octal: test alt form */ + { "%o", 15, "17" }, + { "%#o", 15, "017" }, + + { NULL, 0.0, NULL } +}; + +static const struct { + const char *fmt; + double f; + const char *expect; +} fp_tests[] = { + /* basic form, handling of exponent/precision for 0 */ + { "%e", 0.0, "0.000000e+00" }, + { "%f", 0.0, "0.000000" }, + { "%g", 0.0, "0" }, + { "%#g", 0.0, "0.00000" }, + + /* rounding */ + { "%f", 1.1, "1.100000" }, + { "%f", 1.2, "1.200000" }, + { "%f", 1.3, "1.300000" }, + { "%f", 1.4, "1.400000" }, + { "%f", 1.5, "1.500000" }, + + /* correctness in DBL_DIG places */ + { "%.15g", 1.23456789012345, "1.23456789012345" }, + + /* correct choice of notation for %g */ + { "%g", 0.0001, "0.0001" }, + { "%g", 0.00001, "1e-05" }, + { "%g", 123456, "123456" }, + { "%g", 1234567, "1.23457e+06" }, + { "%.7g", 1234567, "1234567" }, + { "%.7g", 12345678, "1.234568e+07" }, + + /* pi in double precision, printed to a few extra places */ + { "%.15f", M_PI, "3.141592653589793" }, + { "%.18f", M_PI, "3.141592653589793116" }, + + /* exact conversion of large integers */ + { "%.0f", 340282366920938463463374607431768211456.0, + "340282366920938463463374607431768211456" }, + + { NULL, 0.0, NULL } +}; + +int test_snprintf(void) +{ + int i, j; + int err=0; + char b[500], *s; + + strcpy(b, "xxxxxxxx"); + TEST(i, snprintf(b, 4, "%d", 123456), 6, "length returned %d != %d"); + TEST_S(b, "123", "incorrect output"); + TEST(i, b[5], 'x', "buffer overrun"); + +#ifndef DISABLE_SLOW_TESTS + errno = 0; + TEST(i, snprintf(NULL, 0, "%.*u", 2147483647, 0), 2147483647, "cannot print max length %d"); + TEST(i, snprintf(NULL, 0, "%.*u ", 2147483647, 0), -1, "integer overflow %d"); + TEST(i, errno, EOVERFLOW, "after overflow: %d != %d"); +#endif + for (j=0; int_tests[j].fmt; j++) { + TEST(i, snprintf(b, sizeof b, int_tests[j].fmt, int_tests[j].i), strlen(b), "%d != %d"); + TEST_S(b, int_tests[j].expect, "bad integer conversion"); + } + + for (j=0; fp_tests[j].fmt; j++) { + TEST(i, snprintf(b, sizeof b, fp_tests[j].fmt, fp_tests[j].f), strlen(b), "%d != %d"); + TEST_S(b, fp_tests[j].expect, "bad floating point conversion"); + } + + return err; +} -- cgit v1.2.1