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Дата изменения: Sat Dec 17 06:09:28 2005 Дата индексирования: Sun Apr 10 22:52:41 2016 Кодировка: Поисковые слова: п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п |
Find the first occurrence in a string of a substring, starting at a specified location, searching backward.
SCANNING
VARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- str I Any character string. substr I Substring to locate in the character string. start I Position to begin looking for substr in str. The function returns the index of the last occurrence of substr in str at or preceding index start.
str is any character string.
substr is a substring to look for in str. Spaces in substr are
significant, including trailing blanks.
start is the position in str to begin looking for substr. start
may range from 0 to n-1, where n is the number of
characters in str.
The function returns the index of the beginning of the last substring of str that begins at or before index start and is equal to substr. If the substring cannot be found after start, the function is returns -1.
None.
posr_c is case sensitive.
An entire family of related CSPICE routines
cpos_c
cposr_c
ncpos_c
ncposr_c
pos_c
posr_c
is described in the Required Reading.
Let string == "AN ANT AND AN ELEPHANT "
012345678901234567890123456789
Normal (Sequential) Searching:
------------------------------
posr_c ( STRING, "AN", 29 ) == 19
posr_c ( STRING, "AN", 18 ) == 11
posr_c ( STRING, "AN", 10 ) == 7
posr_c ( STRING, "AN", 6 ) == 3
posr_c ( STRING, "AN", 2 ) == 0
start out of bounds:
--------------------
posr_c ( STRING, "AN", -6 ) == -1
posr_c ( STRING, "AN", -1 ) == -1
posr_c ( STRING, "AN", 30 ) == 19
posr_c ( STRING, "AN", 43 ) == 19
Significance of Spaces:
-----------------------
posr_c ( STRING, "AN", 29 ) == 19
posr_c ( STRING, " AN", 29 ) == 10
posr_c ( STRING, " AN ", 29 ) == 10
posr_c ( STRING, " AN ", 9 ) == -1
posr_c ( STRING, " AN ", 29 ) == -1
None.
1) The error SPICE(NULLPOINTER) is signaled if either of
the input string pointers is null.
2) If start is less than 0, the search begins at the first
character of the string.
3) If start is greater than or equal to the length of the string,
posr_c returns -1.
4) The function returns -1 if either of the input strings is empty.
None.
N.J. Bachman (JPL) W.L. Taber (JPL)
None.
-CSPICE Version 1.0.0, 15-AUG-2002 (NJB) (WLT)
position of substring reverse search