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comparison lib/stat-time.h @ 14890:b3af6c2a46e4

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stat-time: get_stat_birthtime failure is better-defined * lib/stat-time.h (get_stat_birthtime): If the time is not available, return a timestamp whose tv_sec and tv_nsec values are both -1. Previously, the spec said only that the tv_nsec value was negative. This upward-compatible change simplifies GNU tar a bit.
author Paul Eggert <eggert@cs.ucla.edu>
date Tue, 07 Jun 2011 16:01:33 -0700
parents cbd63e66d32f
children 8250f2777afc
comparison
equal deleted inserted replaced
14889:a78ddb38a66b 14890:b3af6c2a46e4
140 return t; 140 return t;
141 #endif 141 #endif
142 } 142 }
143 143
144 /* Return *ST's birth time, if available; otherwise return a value 144 /* Return *ST's birth time, if available; otherwise return a value
145 with negative tv_nsec. */ 145 with tv_sec and tv_nsec both equal to -1. */
146 static inline struct timespec 146 static inline struct timespec
147 get_stat_birthtime (struct stat const *st) 147 get_stat_birthtime (struct stat const *st)
148 { 148 {
149 struct timespec t; 149 struct timespec t;
150 150
159 time" in st_ctime (!). See 159 time" in st_ctime (!). See
160 <http://msdn2.microsoft.com/de-de/library/14h5k7ff(VS.80).aspx>. */ 160 <http://msdn2.microsoft.com/de-de/library/14h5k7ff(VS.80).aspx>. */
161 t.tv_sec = st->st_ctime; 161 t.tv_sec = st->st_ctime;
162 t.tv_nsec = 0; 162 t.tv_nsec = 0;
163 #else 163 #else
164 /* Birth time is not supported. Set tv_sec to avoid undefined behavior. */ 164 /* Birth time is not supported. */
165 t.tv_sec = -1; 165 t.tv_sec = -1;
166 t.tv_nsec = -1; 166 t.tv_nsec = -1;
167 /* Avoid a "parameter unused" warning. */ 167 /* Avoid a "parameter unused" warning. */
168 (void) st; 168 (void) st;
169 #endif 169 #endif
173 || defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC) 173 || defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC)
174 /* FreeBSD and NetBSD sometimes signal the absence of knowledge by 174 /* FreeBSD and NetBSD sometimes signal the absence of knowledge by
175 using zero. Attempt to work around this problem. Alas, this can 175 using zero. Attempt to work around this problem. Alas, this can
176 report failure even for valid time stamps. Also, NetBSD 176 report failure even for valid time stamps. Also, NetBSD
177 sometimes returns junk in the birth time fields; work around this 177 sometimes returns junk in the birth time fields; work around this
178 bug if it is detected. There's no need to detect negative 178 bug if it is detected. */
179 tv_nsec junk as negative tv_nsec already indicates an error. */ 179 if (! (t.tv_sec && 0 <= t.tv_nsec && t.tv_nsec < 1000000000))
180 if (t.tv_sec == 0 || 1000000000 <= t.tv_nsec) 180 {
181 t.tv_nsec = -1; 181 t.tv_sec = -1;
182 t.tv_nsec = -1;
183 }
182 #endif 184 #endif
183 185
184 return t; 186 return t;
185 } 187 }
186 188