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tar: code shrink

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function                                             old     new   delta
writeLongname                                        226     228      +2
static.prefilled                                      48       -     -48
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/0 up/down: 2/-48)             Total: -46 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2019-08-01 15:07:21 +02:00
parent 943e81f5db
commit e6a87e7483
1 changed files with 13 additions and 12 deletions
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25
archival/tar.c
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@ -232,7 +232,7 @@ static HardLinkInfo *findHardLinkInfo(HardLinkInfo *hlInfo, struct stat *statbuf
}
/* Put an octal string into the specified buffer.
* The number is zero padded and possibly null terminated.
* The number is zero padded and possibly NUL terminated.
* Stores low-order bits only if whole value does not fit. */
static void putOctal(char *cp, int len, off_t value)
{
@ -283,31 +283,32 @@ static void chksum_and_xwrite(int fd, struct tar_header_t* hp)
# if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
static void writeLongname(int fd, int type, const char *name, int dir)
{
static const struct {
struct prefilled {
char mode[8]; /* 100-107 */
char uid[8]; /* 108-115 */
char gid[8]; /* 116-123 */
char size[12]; /* 124-135 */
char mtime[12]; /* 136-147 */
} prefilled = {
"0000000",
"0000000",
"0000000",
"00000000000",
"00000000000",
};
struct tar_header_t header;
int size;
memset(&header, 0, sizeof(header));
header.typeflag = type;
strcpy(header.name, "././@LongLink");
/* This sets mode/uid/gid/mtime to "00...00<NUL>" strings */
memset(header.mode, '0', sizeof(struct prefilled));
header.mode [sizeof(header.mode ) - 1] = '\0';
header.uid [sizeof(header.uid ) - 1] = '\0';
header.gid [sizeof(header.gid ) - 1] = '\0';
/* header.size is filled by '0' now, will be corrected below */
header.mtime[sizeof(header.mtime) - 1] = '\0';
dir = !!dir; /* normalize: 0/1 */
size = strlen(name) + 1 + dir; /* GNU tar uses strlen+1 */
/* + dir: account for possible '/' */
memset(&header, 0, sizeof(header));
strcpy(header.name, "././@LongLink");
memcpy(header.mode, prefilled.mode, sizeof(prefilled));
PUT_OCTAL(header.size, size);
header.typeflag = type;
chksum_and_xwrite(fd, &header);
/* Write filename[/] and pad the block. */