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authorMattias Andrée <maandree@kth.se>2018-10-20 20:48:13 +0200
committerMattias Andrée <maandree@kth.se>2018-10-20 20:48:13 +0200
commit8f5bd0f85282e044da867bf12c38144b5131e915 (patch)
treef0bf62c380688942e4dedab69016bac1edc5c3ee
parentAdd man pages for memmem and memrmem (diff)
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Add memelem and memrelem
Signed-off-by: Mattias Andrée <maandree@kth.se>
-rw-r--r--Makefile2
-rw-r--r--libsimple/mem.h38
-rw-r--r--man/libsimple_memelem.382
-rw-r--r--man/libsimple_memmem.31
-rw-r--r--man/libsimple_memrelem.382
-rw-r--r--man/libsimple_memrmem.31
-rw-r--r--memelem.c73
-rw-r--r--memrelem.c82
8 files changed, 361 insertions, 0 deletions
diff --git a/Makefile b/Makefile
index cb3628a..9071f61 100644
--- a/Makefile
+++ b/Makefile
@@ -60,9 +60,11 @@ OBJ =\
envreallocn.o\
isutf8.o\
memdup.o\
+ memelem.o\
memends.o\
memmem.o\
memrchr.o\
+ memrelem.o\
memrmem.o\
memstarts.o\
minimise_number_string.o\
diff --git a/libsimple/mem.h b/libsimple/mem.h
index cf5a866..bd20a49 100644
--- a/libsimple/mem.h
+++ b/libsimple/mem.h
@@ -95,6 +95,44 @@ void *libsimple_memrmem(const void *, size_t, const void *, size_t);
#endif
+/**
+ * Finds the first element in an array
+ *
+ * @param haystack The array of bytes to search
+ * @param nhaystack The length of `haystack`, divided by `needle`
+ * @param needle The substring to search for
+ * @param nneedle The length of `needle`
+ * @return `haystack` with a minimal offset such that,
+ * `!memcmp(r, needle, nneedle)` where `r` is the
+ * returned pointer and such that `(r - haystack) % nneedle == 0`,
+ * `NULL` if no such offset exists
+ */
+_LIBSIMPLE_GCC_ONLY(__attribute__((__pure__, __warn_unused_result__)))
+void *libsimple_memelem(const void *, size_t, const void *, size_t);
+#ifndef memelem
+# define memelem libsimple_memelem
+#endif
+
+
+/**
+ * Finds the last element in an array
+ *
+ * @param haystack The array of bytes to search
+ * @param nhaystack The length of `haystack`, divided by `needle`
+ * @param needle The substring to search for
+ * @param nneedle The length of `needle`
+ * @return `haystack` with a maximal offset such that,
+ * `!memcmp(r, needle, nneedle)` where `r` is the
+ * returned pointer and such that `(r - haystack) % nneedle == 0`,
+ * `NULL` if no such offset exists
+ */
+_LIBSIMPLE_GCC_ONLY(__attribute__((__pure__, __warn_unused_result__)))
+void *libsimple_memrelem(const void *, size_t, const void *, size_t);
+#ifndef memrelem
+# define memrelem libsimple_memrelem
+#endif
+
+
_LIBSIMPLE_GCC_ONLY(__attribute__((__pure__, __warn_unused_result__)))
int libsimple_memstarts(const void *, size_t, const void *, size_t);
#ifndef memstarts
diff --git a/man/libsimple_memelem.3 b/man/libsimple_memelem.3
new file mode 100644
index 0000000..be182c3
--- /dev/null
+++ b/man/libsimple_memelem.3
@@ -0,0 +1,82 @@
+.TH LIBSIMPLE_MEMELEM 3 2018-10-20 libsimple
+.SH NAME
+libsimple_memelem \- find byte string in memory
+.SH SYNOPSIS
+.nf
+#include <libsimple.h>
+
+void *libsimple_memelem(const void *haystack, size_t nhaystack, const void *needle, size_t nneedle);
+
+#ifndef memelem
+# define memelem libsimple_memelem
+#endif
+.fi
+
+Link with
+.IR \-lsimple .
+.SH DESCRIPTION
+The
+.BR libsimple_memelem ()
+function scans the memory segment
+.IR haystack ,
+with the size
+.IR nhaystack*nneedle ,
+for the first occurence of the byte string
+.I needle
+with the size
+.IR nneedle ,
+and with an offset equivalent to zero modulo
+.IR nneedle .
+.SH RETURN VALUE
+The
+.BR libsimple_memelem ()
+function returns the pointer
+.I s
+with a minimal offset such that
+.IR !memcmp(r,needle,nneedle) ,
+where
+.I r
+is the returned pointer, and such that
+the offset is equivalent to zero modulo
+.IR nneedle .
+If no such offset exists,
+.B NULL
+is returned.
+.SH ERRORS
+The
+.BR libsimple_memelem ()
+function cannot fail.
+.SH ATTRIBUTES
+For an explanation of the terms used in this section, see
+.BR attributes (7).
+.TS
+allbox;
+lb lb lb
+l l l.
+Interface Attribute Value
+T{
+.BR libsimple_memelem ()
+T} Thread safety MT-Safe
+T{
+.BR libsimple_memelem ()
+T} Async-signal safety AS-Safe
+T{
+.BR libsimple_memelem ()
+T} Async-cancel safety AC-Safe
+.TE
+.SH EXAMPLES
+None.
+.SH APPLICATION USAGE
+None.
+.SH RATIONALE
+None.
+.SH FUTURE DIRECTIONS
+None.
+.SH NOTES
+None.
+.SH BUGS
+None.
+.SH SEE ALSO
+.BR libsimple_memrelem (3),
+.BR libsimple_memmem (3),
+.BR memchr (3)
diff --git a/man/libsimple_memmem.3 b/man/libsimple_memmem.3
index f084de9..6701b46 100644
--- a/man/libsimple_memmem.3
+++ b/man/libsimple_memmem.3
@@ -74,4 +74,5 @@ None.
None.
.SH SEE ALSO
.BR libsimple_memrmem (3),
+.BR libsimple_memelem (3),
.BR memchr (3)
diff --git a/man/libsimple_memrelem.3 b/man/libsimple_memrelem.3
new file mode 100644
index 0000000..77f5293
--- /dev/null
+++ b/man/libsimple_memrelem.3
@@ -0,0 +1,82 @@
+.TH LIBSIMPLE_MEMRELEM 3 2018-10-20 libsimple
+.SH NAME
+libsimple_memrelem \- find byte string in memory
+.SH SYNOPSIS
+.nf
+#include <libsimple.h>
+
+void *libsimple_memrelem(const void *haystack, size_t nhaystack, const void *needle, size_t nneedle);
+
+#ifndef memrelem
+# define memrelem libsimple_memrelem
+#endif
+.fi
+
+Link with
+.IR \-lsimple .
+.SH DESCRIPTION
+The
+.BR libsimple_memrelem ()
+function scans the memory segment
+.IR haystack ,
+with the size
+.IR nhaystack*nneedle ,
+for the last occurence of the byte string
+.I needle
+with the size
+.IR nneedle ,
+and with an offset equivalent to zero modulo
+.IR nneedle .
+.SH RETURN VALUE
+The
+.BR libsimple_memrelem ()
+function returns the pointer
+.I s
+with a maximal offset such that
+.IR !memcmp(r,needle,nneedle) ,
+where
+.I r
+is the returned pointer, and such that
+the offset is equivalent to zero modulo
+.IR nneedle .
+If no such offset exists,
+.B NULL
+is returned.
+.SH ERRORS
+The
+.BR libsimple_memrelem ()
+function cannot fail.
+.SH ATTRIBUTES
+For an explanation of the terms used in this section, see
+.BR attributes (7).
+.TS
+allbox;
+lb lb lb
+l l l.
+Interface Attribute Value
+T{
+.BR libsimple_memrelem ()
+T} Thread safety MT-Safe
+T{
+.BR libsimple_memrelem ()
+T} Async-signal safety AS-Safe
+T{
+.BR libsimple_memrelem ()
+T} Async-cancel safety AC-Safe
+.TE
+.SH EXAMPLES
+None.
+.SH APPLICATION USAGE
+None.
+.SH RATIONALE
+None.
+.SH FUTURE DIRECTIONS
+None.
+.SH NOTES
+None.
+.SH BUGS
+None.
+.SH SEE ALSO
+.BR libsimple_memelem (3),
+.BR libsimple_memrmem (3),
+.BR libsimple_memrchr (3)
diff --git a/man/libsimple_memrmem.3 b/man/libsimple_memrmem.3
index 71bf251..c9daf17 100644
--- a/man/libsimple_memrmem.3
+++ b/man/libsimple_memrmem.3
@@ -74,4 +74,5 @@ None.
None.
.SH SEE ALSO
.BR libsimple_memmem (3),
+.BR libsimple_memrelem (3),
.BR libsimple_memrchr (3)
diff --git a/memelem.c b/memelem.c
new file mode 100644
index 0000000..2561456
--- /dev/null
+++ b/memelem.c
@@ -0,0 +1,73 @@
+/* See LICENSE file for copyright and license details. */
+#include "libsimple.h"
+#ifndef TEST
+
+
+void *
+libsimple_memelem(const void *hay_, size_t hayn, const void *sub_, size_t subn)
+{
+ if (!subn)
+ return (void *)hay_;
+
+ switch (subn) {
+ case 1:
+ return memchr(hay_, hayn, *(char *)sub_);
+ case 2:
+ {
+ uint16_t *hay = (void *)hay_;
+ uint16_t sub = *(uint16_t *)sub_;
+ for (; hayn--; hay++)
+ if (*hay == sub)
+ return hay;
+ break;
+ }
+ case 4:
+ {
+ uint32_t *hay = (void *)hay_;
+ uint32_t sub = *(uint32_t *)sub_;
+ for (; hayn--; hay++)
+ if (*hay == sub)
+ return hay;
+ break;
+ }
+ case 8:
+ {
+ uint64_t *hay = (void *)hay_;
+ uint64_t sub = *(uint64_t *)sub_;
+ for (; hayn--; hay++)
+ if (*hay == sub)
+ return hay;
+ break;
+ }
+ default:
+ {
+ char *hay = (void *)hay_;
+ const char *sub = sub_;
+ for (; hayn--; hay += subn)
+ if (!memcmp(hay, sub, subn))
+ return hay;
+ break;
+
+ }
+ }
+
+ return NULL;
+}
+
+
+#else
+#include "test.h"
+
+int
+main(void)
+{
+ assert(!strcmpnul(libsimple_memelem("12345634", 4, "", 0), "12345634"));
+ assert(!strcmpnul(libsimple_memelem("12345634", 4, "34", 2), "345634"));
+ assert(!libsimple_memelem("12345634", 4, "xx", 2));
+ assert(!libsimple_memelem("13456342", 4, "34", 2));
+ assert(!libsimple_memelem("12345634", 0, "34", 2));
+ assert(!strcmpnul(libsimple_memelem("12345634", 0, "34", 0), "12345634"));
+ return 0;
+}
+
+#endif
diff --git a/memrelem.c b/memrelem.c
new file mode 100644
index 0000000..cc11d9e
--- /dev/null
+++ b/memrelem.c
@@ -0,0 +1,82 @@
+/* See LICENSE file for copyright and license details. */
+#include "libsimple.h"
+#ifndef TEST
+
+
+void *
+libsimple_memrelem(const void *hay_, size_t hayn, const void *sub_, size_t subn)
+{
+ if (!subn)
+ return (void *)hay_;
+
+ switch (subn) {
+ case 1:
+ {
+ uint8_t *hay = (void *)hay_;
+ uint8_t sub = *(uint8_t *)sub_;
+ for (hay += hayn; hayn--;)
+ if (*--hay == sub)
+ return hay;
+ break;
+ }
+ case 2:
+ {
+ uint16_t *hay = (void *)hay_;
+ uint16_t sub = *(uint16_t *)sub_;
+ for (hay += hayn; hayn--;)
+ if (*--hay == sub)
+ return hay;
+ break;
+ }
+ case 4:
+ {
+ uint32_t *hay = (void *)hay_;
+ uint32_t sub = *(uint32_t *)sub_;
+ for (hay += hayn; hayn--;)
+ if (*--hay == sub)
+ return hay;
+ break;
+ }
+ case 8:
+ {
+ uint64_t *hay = (void *)hay_;
+ uint64_t sub = *(uint64_t *)sub_;
+ for (hay += hayn; hayn--;)
+ if (*--hay == sub)
+ return hay;
+ break;
+ }
+ default:
+ {
+ char *hay = (void *)hay_;
+ const char *sub = sub_;
+ for (hay += hayn * subn; hayn--;) {
+ hay -= subn;
+ if (!memcmp(hay, sub, subn))
+ return hay;
+ }
+ break;
+
+ }
+ }
+
+ return NULL;
+}
+
+
+#else
+#include "test.h"
+
+int
+main(void)
+{
+ assert(!strcmpnul(libsimple_memrelem("12345634", 4, "", 0), "12345634"));
+ assert(!strcmpnul(libsimple_memrelem("12345634", 4, "34", 2), "34"));
+ assert(!libsimple_memrelem("12345634", 4, "xx", 2));
+ assert(!libsimple_memrelem("13456342", 4, "34", 2));
+ assert(!libsimple_memrelem("12345634", 0, "34", 2));
+ assert(!strcmpnul(libsimple_memrelem("12345634", 0, "34", 0), "12345634"));
+ return 0;
+}
+
+#endif