/* lib.c - various reusable stuff.
*
* Copyright 2006 Rob Landley <rob@landley.net>
*/
#include "toys.h"
void verror_msg(char *msg, int err, va_list va)
{
char *s = ": %s";
fprintf(stderr, "%s: ", toys.which->name);
if (msg) vfprintf(stderr, msg, va);
else s+=2;
if (err) fprintf(stderr, s, strerror(err));
if (msg || err) putc('\n', stderr);
if (!toys.exitval) toys.exitval++;
}
// These functions don't collapse together because of the va_stuff.
void error_msg(char *msg, ...)
{
va_list va;
va_start(va, msg);
verror_msg(msg, 0, va);
va_end(va);
}
void perror_msg(char *msg, ...)
{
va_list va;
va_start(va, msg);
verror_msg(msg, errno, va);
va_end(va);
}
// Die with an error message.
void error_exit(char *msg, ...)
{
va_list va;
va_start(va, msg);
verror_msg(msg, 0, va);
va_end(va);
xexit();
}
// Die with an error message and strerror(errno)
void perror_exit(char *msg, ...)
{
va_list va;
va_start(va, msg);
verror_msg(msg, errno, va);
va_end(va);
xexit();
}
// Exit with an error message after showing help text.
void help_exit(char *msg, ...)
{
va_list va;
if (CFG_TOYBOX_HELP) show_help(stderr);
if (msg) {
va_start(va, msg);
verror_msg(msg, 0, va);
va_end(va);
}
xexit();
}
// If you want to explicitly disable the printf() behavior (because you're
// printing user-supplied data, or because android's static checker produces
// false positives for 'char *s = x ? "blah1" : "blah2"; printf(s);' and it's
// -Werror there for policy reasons).
void error_msg_raw(char *msg)
{
error_msg("%s", msg);
}
void perror_msg_raw(char *msg)
{
perror_msg("%s", msg);
}
void error_exit_raw(char *msg)
{
error_exit("%s", msg);
}
void perror_exit_raw(char *msg)
{
perror_exit("%s", msg);
}
// Keep reading until full or EOF
ssize_t readall(int fd, void *buf, size_t len)
{
size_t count = 0;
while (count<len) {
int i = read(fd, (char *)buf+count, len-count);
if (!i) break;
if (i<0) return i;
count += i;
}
return count;
}
// Keep writing until done or EOF
ssize_t writeall(int fd, void *buf, size_t len)
{
size_t count = 0;
while (count<len) {
int i = write(fd, count+(char *)buf, len-count);
if (i<1) return i;
count += i;
}
return count;
}
// skip this many bytes of input. Return 0 for success, >0 means this much
// left after input skipped.
off_t lskip(int fd, off_t offset)
{
off_t cur = lseek(fd, 0, SEEK_CUR);
if (cur != -1) {
off_t end = lseek(fd, 0, SEEK_END) - cur;
if (end > 0 && end < offset) return offset - end;
end = offset+cur;
if (end == lseek(fd, end, SEEK_SET)) return 0;
perror_exit("lseek");
}
while (offset>0) {
int try = offset>sizeof(libbuf) ? sizeof(libbuf) : offset, or;
or = readall(fd, libbuf, try);
if (or < 0) perror_exit("lskip to %lld", (long long)offset);
else offset -= or;
if (or < try) break;
}
return offset;
}
// flags: 1=make last dir (with mode lastmode, otherwise skips last component)
// 2=make path (already exists is ok)
// 4=verbose
// returns 0 = path ok, 1 = error
int mkpathat(int atfd, char *dir, mode_t lastmode, int flags)
{
struct stat buf;
char *s;
// mkdir -p one/two/three is not an error if the path already exists,
// but is if "three" is a file. The others we dereference and catch
// not-a-directory along the way, but the last one we must explicitly
// test for. Might as well do it up front.
if (!fstatat(atfd, dir, &buf, 0) && !S_ISDIR(buf.st_mode)) {
errno = EEXIST;
return 1;
}
for (s = dir; ;s++) {
char save = 0;
mode_t mode = (0777&~toys.old_umask)|0300;
// find next '/', but don't try to mkdir "" at start of absolute path
if (*s == '/' && (flags&2) && s != dir) {
save = *s;
*s = 0;
} else if (*s) continue;
// Use the mode from the -m option only for the last directory.
if (!save) {
if (flags&1) mode = lastmode;
else break;
}
if (mkdirat(atfd, dir, mode)) {
if (!(flags&2) || errno != EEXIST) return 1;
} else if (flags&4)
fprintf(stderr, "%s: created directory '%s'\n", toys.which->name, dir);
if (!(*s = save)) break;
}
return 0;
}
// Split a path into linked list of components, tracking head and tail of list.
// Filters out // entries with no contents.
struct string_list **splitpath(char *path, struct string_list **list)
{
char *new = path;
*list = 0;
do {
int len;
if (*path && *path != '/') continue;
len = path-new;
if (len > 0) {
*list = xmalloc(sizeof(struct string_list) + len + 1);
(*list)->next = 0;
memcpy((*list)->str, new, len);
(*list)->str[len] = 0;
list = &(*list)->next;
}
new = path+1;
} while (*path++);
return list;
}
// Find all file in a colon-separated path with access type "type" (generally
// X_OK or R_OK). Returns a list of absolute paths to each file found, in
// order.
struct string_list *find_in_path(char *path, char *filename)
{
struct string_list *rlist = NULL, **prlist=&rlist;
char *cwd;
if (!path) return 0;
cwd = xgetcwd();
for (;;) {
char *next = strchr(path, ':');
int len = next ? next-path : strlen(path);
struct string_list *rnext;
struct stat st;
rnext = xmalloc(sizeof(void *) + strlen(filename)
+ (len ? len : strlen(cwd)) + 2);
if (!len) sprintf(rnext->str, "%s/%s", cwd, filename);
else {
char *res = rnext->str;
memcpy(res, path, len);
res += len;
*(res++) = '/';
strcpy(res, filename);
}
// Confirm it's not a directory.
if (!stat(rnext->str, &st) && S_ISREG(st.st_mode)) {
*prlist = rnext;
rnext->next = NULL;
prlist = &(rnext->next);
} else free(rnext);
if (!next) break;
path += len;
path++;
}
free(cwd);
return rlist;
}
long estrtol(char *str, char **end, int base)
{
errno = 0;
return strtol(str, end, base);
}
long xstrtol(char *str, char **end, int base)
{
long l = estrtol(str, end, base);
if (errno) perror_exit_raw(str);
return l;
}
// atol() with the kilo/mega/giga/tera/peta/exa extensions.
// (zetta and yotta don't fit in 64 bits.)
long atolx(char *numstr)
{
char *c, *suffixes="cbkmgtpe", *end;
long val;
val = xstrtol(numstr, &c, 0);
if (*c) {
if (c != numstr && (end = strchr(suffixes, tolower(*c)))) {
int shift = end-suffixes-2;
if (shift >= 0) val *= 1024L<<(shift*10);
} else {
while (isspace(*c)) c++;
if (*c) error_exit("not integer: %s", numstr);
}
}
return val;
}
long atolx_range(char *numstr, long low, long high)
{
long val = atolx(numstr);
if (val < low) error_exit("%ld < %ld", val, low);
if (val > high) error_exit("%ld > %ld", val, high);
return val;
}
int stridx(char *haystack, char needle)
{
char *off;
if (!needle) return -1;
off = strchr(haystack, needle);
if (!off) return -1;
return off-haystack;
}
char *strlower(char *s)
{
char *try, *new;
if (!CFG_TOYBOX_I18N) {
try = new = xstrdup(s);
for (; *s; s++) *(new++) = tolower(*s);
} else {
// I can't guarantee the string _won't_ expand during reencoding, so...?
try = new = xmalloc(strlen(s)*2+1);
while (*s) {
wchar_t c;
int len = mbrtowc(&c, s, MB_CUR_MAX, 0);
if (len < 1) *(new++) = *(s++);
else {
s += len;
// squash title case too
c = towlower(c);
// if we had a valid utf8 sequence, convert it to lower case, and can't
// encode back to utf8, something is wrong with your libc. But just
// in case somebody finds an exploit...
len = wcrtomb(new, c, 0);
if (len < 1) error_exit("bad utf8 %x", (int)c);
new += len;
}
}
*new = 0;
}
return try;
}
// strstr but returns pointer after match
char *strafter(char *haystack, char *needle)
{
char *s = strstr(haystack, needle);
return s ? s+strlen(needle) : s;
}
// Remove trailing \n
char *chomp(char *s)
{
char *p = strrchr(s, '\n');
if (p && !p[1]) *p = 0;
return s;
}
int unescape(char c)
{
char *from = "\\abefnrtv", *to = "\\\a\b\033\f\n\r\t\v";
int idx = stridx(from, c);
return (idx == -1) ? 0 : to[idx];
}
// If *a starts with b, advance *a past it and return 1, else return 0;
int strstart(char **a, char *b)
{
int len = strlen(b), i = !strncmp(*a, b, len);
if (i) *a += len;
return i;
}
// Return how long the file at fd is, if there's any way to determine it.
off_t fdlength(int fd)
{
struct stat st;
off_t base = 0, range = 1, expand = 1, old;
if (!fstat(fd, &st) && S_ISREG(st.st_mode)) return st.st_size;
// If the ioctl works for this, return it.
// TODO: is blocksize still always 512, or do we stat for it?
// unsigned int size;
// if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512L;
// If not, do a binary search for the last location we can read. (Some
// block devices don't do BLKGETSIZE right.) This should probably have
// a CONFIG option...
// If not, do a binary search for the last location we can read.
old = lseek(fd, 0, SEEK_CUR);
do {
char temp;
off_t pos = base + range / 2;
if (lseek(fd, pos, 0)>=0 && read(fd, &temp, 1)==1) {
off_t delta = (pos + 1) - base;
base += delta;
if (expand) range = (expand <<= 1) - base;
else range -= delta;
} else {
expand = 0;
range = pos - base;
}
} while (range > 0);
lseek(fd, old, SEEK_SET);
return base;
}
// Read contents of file as a single nul-terminated string.
// measure file size if !len, allocate buffer if !buf
// note: for existing buffers use len = size-1, will set buf[len] = 0
char *readfileat(int dirfd, char *name, char *ibuf, off_t *plen)
{
off_t len, rlen;
int fd;
char *buf, *rbuf;
// Unsafe to probe for size with a supplied buffer, don't ever do that.
if (CFG_TOYBOX_DEBUG && (ibuf ? !*plen : *plen)) error_exit("bad readfileat");
if (-1 == (fd = openat(dirfd, name, O_RDONLY))) return 0;
// If we dunno the length, probe it. If we can't probe, start with 1 page.
if (!*plen) {
if ((len = fdlength(fd))>0) *plen = len;
else len = 4096;
} else len = *plen-1;
if (!ibuf) buf = xmalloc(len+1);
else buf = ibuf;
for (rbuf = buf;;) {
rlen = readall(fd, rbuf, len);
if (*plen || rlen<len) break;
// If reading unknown size, expand buffer by 1.5 each time we fill it up.
rlen += rbuf-buf;
buf = xrealloc(buf, len = (rlen*3)/2);
rbuf = buf+rlen;
len -= rlen;
}
*plen = len = rlen+(rbuf-buf);
close(fd);
if (rlen<0) {
if (ibuf != buf) free(buf);
buf = 0;
} else buf[len] = 0;
return buf;
}
char *readfile(char *name, char *ibuf, off_t len)
{
return readfileat(AT_FDCWD, name, ibuf, &len);
}
// Sleep for this many thousandths of a second
void msleep(long miliseconds)
{
struct timespec ts;
ts.tv_sec = miliseconds/1000;
ts.tv_nsec = (miliseconds%1000)*1000000;
nanosleep(&ts, &ts);
}
// Inefficient, but deals with unaligned access
int64_t peek_le(void *ptr, unsigned size)
{
int64_t ret = 0;
char *c = ptr;
int i;
for (i=0; i<size; i++) ret |= ((int64_t)c[i])<<(i*8);
return ret;
}
int64_t peek_be(void *ptr, unsigned size)
{
int64_t ret = 0;
char *c = ptr;
int i;
for (i=0; i<size; i++) ret = (ret<<8)|(c[i]&0xff);
return ret;
}
int64_t peek(void *ptr, unsigned size)
{
return IS_BIG_ENDIAN ? peek_be(ptr, size) : peek_le(ptr, size);
}
void poke(void *ptr, uint64_t val, int size)
{
if (size & 8) {
volatile uint64_t *p = (uint64_t *)ptr;
*p = val;
} else if (size & 4) {
volatile int *p = (int *)ptr;
*p = val;
} else if (size & 2) {
volatile short *p = (short *)ptr;
*p = val;
} else {
volatile char *p = (char *)ptr;
*p = val;
}
}
// Iterate through an array of files, opening each one and calling a function
// on that filehandle and name. The special filename "-" means stdin if
// flags is O_RDONLY, stdout otherwise. An empty argument list calls
// function() on just stdin/stdout.
//
// Note: pass O_CLOEXEC to automatically close filehandles when function()
// returns, otherwise filehandles must be closed by function()
void loopfiles_rw(char **argv, int flags, int permissions, int failok,
void (*function)(int fd, char *name))
{
int fd;
// If no arguments, read from stdin.
if (!*argv) function((flags & O_ACCMODE) != O_RDONLY ? 1 : 0, "-");
else do {
// Filename "-" means read from stdin.
// Inability to open a file prints a warning, but doesn't exit.
if (!strcmp(*argv, "-")) fd=0;
else if (0>(fd = open(*argv, flags, permissions)) && !failok) {
perror_msg_raw(*argv);
continue;
}
function(fd, *argv);
if (flags & O_CLOEXEC) close(fd);
} while (*++argv);
}
// Call loopfiles_rw with O_RDONLY|O_CLOEXEC and !failok (common case).
void loopfiles(char **argv, void (*function)(int fd, char *name))
{
loopfiles_rw(argv, O_RDONLY|O_CLOEXEC, 0, 0, function);
}
// Slow, but small.
char *get_rawline(int fd, long *plen, char end)
{
char c, *buf = NULL;
long len = 0;
for (;;) {
if (1>read(fd, &c, 1)) break;
if (!(len & 63)) buf=xrealloc(buf, len+65);
if ((buf[len++]=c) == end) break;
}
if (buf) buf[len]=0;
if (plen) *plen = len;
return buf;
}
char *get_line(int fd)
{
long len;
char *buf = get_rawline(fd, &len, '\n');
if (buf && buf[--len]=='\n') buf[len]=0;
return buf;
}
int wfchmodat(int fd, char *name, mode_t mode)
{
int rc = fchmodat(fd, name, mode, 0);
if (rc) {
perror_msg("chmod '%s' to %04o", name, mode);
toys.exitval=1;
}
return rc;
}
static char *tempfile2zap;
static void tempfile_handler(int i)
{
if (1 < (long)tempfile2zap) unlink(tempfile2zap);
_exit(1);
}
// Open a temporary file to copy an existing file into.
int copy_tempfile(int fdin, char *name, char **tempname)
{
struct stat statbuf;
int fd;
*tempname = xmprintf("%s%s", name, "XXXXXX");
if(-1 == (fd = mkstemp(*tempname))) error_exit("no temp file");
if (!tempfile2zap) sigatexit(tempfile_handler);
tempfile2zap = *tempname;
// Set permissions of output file
fstat(fdin, &statbuf);
fchmod(fd, statbuf.st_mode);
return fd;
}
// Abort the copy and delete the temporary file.
void delete_tempfile(int fdin, int fdout, char **tempname)
{
close(fdin);
close(fdout);
if (*tempname) unlink(*tempname);
tempfile2zap = (char *)1;
free(*tempname);
*tempname = NULL;
}
// Copy the rest of the data and replace the original with the copy.
void replace_tempfile(int fdin, int fdout, char **tempname)
{
char *temp = xstrdup(*tempname);
temp[strlen(temp)-6]=0;
if (fdin != -1) {
xsendfile(fdin, fdout);
xclose(fdin);
}
xclose(fdout);
rename(*tempname, temp);
tempfile2zap = (char *)1;
free(*tempname);
free(temp);
*tempname = NULL;
}
// Create a 256 entry CRC32 lookup table.
void crc_init(unsigned int *crc_table, int little_endian)
{
unsigned int i;
// Init the CRC32 table (big endian)
for (i=0; i<256; i++) {
unsigned int j, c = little_endian ? i : i<<24;
for (j=8; j; j--)
if (little_endian) c = (c&1) ? (c>>1)^0xEDB88320 : c>>1;
else c=c&0x80000000 ? (c<<1)^0x04c11db7 : (c<<1);
crc_table[i] = c;
}
}
// Init base64 table
void base64_init(char *p)
{
int i;
for (i = 'A'; i != ':'; i++) {
if (i == 'Z'+1) i = 'a';
if (i == 'z'+1) i = '0';
*(p++) = i;
}
*(p++) = '+';
*(p++) = '/';
}
int yesno(int def)
{
char buf;
fprintf(stderr, " (%c/%c):", def ? 'Y' : 'y', def ? 'n' : 'N');
fflush(stderr);
while (fread(&buf, 1, 1, stdin)) {
int new;
// The letter changes the value, the newline (or space) returns it.
if (isspace(buf)) break;
if (-1 != (new = stridx("ny", tolower(buf)))) def = new;
}
return def;
}
struct signame {
int num;
char *name;
};
// Signals required by POSIX 2008:
// http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/signal.h.html
#define SIGNIFY(x) {SIG##x, #x}
static struct signame signames[] = {
SIGNIFY(ABRT), SIGNIFY(ALRM), SIGNIFY(BUS),
SIGNIFY(FPE), SIGNIFY(HUP), SIGNIFY(ILL), SIGNIFY(INT), SIGNIFY(KILL),
SIGNIFY(PIPE), SIGNIFY(QUIT), SIGNIFY(SEGV), SIGNIFY(TERM),
SIGNIFY(USR1), SIGNIFY(USR2), SIGNIFY(SYS), SIGNIFY(TRAP),
SIGNIFY(VTALRM), SIGNIFY(XCPU), SIGNIFY(XFSZ),
// Start of non-terminal signals
SIGNIFY(CHLD), SIGNIFY(CONT), SIGNIFY(STOP), SIGNIFY(TSTP),
SIGNIFY(TTIN), SIGNIFY(TTOU), SIGNIFY(URG)
};
// not in posix: SIGNIFY(STKFLT), SIGNIFY(WINCH), SIGNIFY(IO), SIGNIFY(PWR)
// obsolete: SIGNIFY(PROF) SIGNIFY(POLL)
// Handler that sets toys.signal, and writes to toys.signalfd if set
void generic_signal(int sig)
{
if (toys.signalfd) {
char c = sig;
writeall(toys.signalfd, &c, 1);
}
toys.signal = sig;
}
// Install the same handler on every signal that defaults to killing the process
void sigatexit(void *handler)
{
int i;
for (i=0; signames[i].num != SIGCHLD; i++) signal(signames[i].num, handler);
}
// Convert name to signal number. If name == NULL print names.
int sig_to_num(char *pidstr)
{
int i;
if (pidstr) {
char *s;
i = estrtol(pidstr, &s, 10);
if (!errno && !*s) return i;
if (!strncasecmp(pidstr, "sig", 3)) pidstr+=3;
}
for (i = 0; i < sizeof(signames)/sizeof(struct signame); i++)
if (!pidstr) xputs(signames[i].name);
else if (!strcasecmp(pidstr, signames[i].name)) return signames[i].num;
return -1;
}
char *num_to_sig(int sig)
{
int i;
for (i=0; i<sizeof(signames)/sizeof(struct signame); i++)
if (signames[i].num == sig) return signames[i].name;
return NULL;
}
// premute mode bits based on posix mode strings.
mode_t string_to_mode(char *modestr, mode_t mode)
{
char *whos = "ogua", *hows = "=+-", *whats = "xwrstX", *whys = "ogu",
*s, *str = modestr;
mode_t extrabits = mode & ~(07777);
// Handle octal mode
if (isdigit(*str)) {
mode = estrtol(str, &s, 8);
if (errno || *s || (mode & ~(07777))) goto barf;
return mode | extrabits;
}
// Gaze into the bin of permission...
for (;;) {
int i, j, dowho, dohow, dowhat, amask;
dowho = dohow = dowhat = amask = 0;
// Find the who, how, and what stanzas, in that order
while (*str && (s = strchr(whos, *str))) {
dowho |= 1<<(s-whos);
str++;
}
// If who isn't specified, like "a" but honoring umask.
if (!dowho) {
dowho = 8;
umask(amask=umask(0));
}
if (!*str || !(s = strchr(hows, *str))) goto barf;
dohow = *(str++);
if (!dohow) goto barf;
while (*str && (s = strchr(whats, *str))) {
dowhat |= 1<<(s-whats);
str++;
}
// Convert X to x for directory or if already executable somewhere
if ((dowhat&32) && (S_ISDIR(mode) || (mode&0111))) dowhat |= 1;
// Copy mode from another category?
if (!dowhat && *str && (s = strchr(whys, *str))) {
dowhat = (mode>>(3*(s-whys)))&7;
str++;
}
// Are we ready to do a thing yet?
if (*str && *(str++) != ',') goto barf;
// Ok, apply the bits to the mode.
for (i=0; i<4; i++) {
for (j=0; j<3; j++) {
mode_t bit = 0;
int where = 1<<((3*i)+j);
if (amask & where) continue;
// Figure out new value at this location
if (i == 3) {
// suid/sticky bit.
if (j) {
if ((dowhat & 8) && (dowho&(8|(1<<i)))) bit++;
} else if (dowhat & 16) bit++;
} else {
if (!(dowho&(8|(1<<i)))) continue;
if (dowhat&(1<<j)) bit++;
}
// When selection active, modify bit
if (dohow == '=' || (bit && dohow == '-')) mode &= ~where;
if (bit && dohow != '-') mode |= where;
}
}
if (!*str) break;
}
return mode|extrabits;
barf:
error_exit("bad mode '%s'", modestr);
}
// Format access mode into a drwxrwxrwx string
void mode_to_string(mode_t mode, char *buf)
{
char c, d;
int i, bit;
buf[10]=0;
for (i=0; i<9; i++) {
bit = mode & (1<<i);
c = i%3;
if (!c && (mode & (1<<((d=i/3)+9)))) {
c = "tss"[d];
if (!bit) c &= ~0x20;
} else c = bit ? "xwr"[c] : '-';
buf[9-i] = c;
}
if (S_ISDIR(mode)) c = 'd';
else if (S_ISBLK(mode)) c = 'b';
else if (S_ISCHR(mode)) c = 'c';
else if (S_ISLNK(mode)) c = 'l';
else if (S_ISFIFO(mode)) c = 'p';
else if (S_ISSOCK(mode)) c = 's';
else c = '-';
*buf = c;
}
char *basename_r(char *name)
{
char *s = strrchr(name, '/');
if (s) return s+1;
return name;
}
// Execute a callback for each PID that matches a process name from a list.
void names_to_pid(char **names, int (*callback)(pid_t pid, char *name))
{
DIR *dp;
struct dirent *entry;
if (!(dp = opendir("/proc"))) perror_exit("opendir");
while ((entry = readdir(dp))) {
unsigned u;
char *cmd, **curname;
if (!(u = atoi(entry->d_name))) continue;
sprintf(libbuf, "/proc/%u/cmdline", u);
if (!(cmd = readfile(libbuf, libbuf, sizeof(libbuf)))) continue;
for (curname = names; *curname; curname++)
if (**curname == '/' ? !strcmp(cmd, *curname)
: !strcmp(basename_r(cmd), basename_r(*curname)))
if (callback(u, *curname)) break;
if (*curname) break;
}
closedir(dp);
}
// display first few digits of number with power of two units
int human_readable(char *buf, unsigned long long num, int style)
{
unsigned long long snap = 0;
int len, unit, divisor = (style&HR_1000) ? 1000 : 1024;
// Divide rounding up until we have 3 or fewer digits. Since the part we
// print is decimal, the test is 999 even when we divide by 1024.
// We can't run out of units because 2<<64 is 18 exabytes.
// test 5675 is 5.5k not 5.6k.
for (unit = 0; num > 999; unit++) num = ((snap = num)+(divisor/2))/divisor;
len = sprintf(buf, "%llu", num);
if (unit && len == 1) {
// Redo rounding for 1.2M case, this works with and without HR_1000.
num = snap/divisor;
snap -= num*divisor;
snap = ((snap*100)+50)/divisor;
snap /= 10;
len = sprintf(buf, "%llu.%llu", num, snap);
}
if (style & HR_SPACE) buf[len++] = ' ';
if (unit) {
unit = " kMGTPE"[unit];
if (!(style&HR_1000)) unit = toupper(unit);
buf[len++] = unit;
} else if (style & HR_B) buf[len++] = 'B';
buf[len] = 0;
return len;
}
// The qsort man page says you can use alphasort, the posix committee
// disagreed, and doubled down: http://austingroupbugs.net/view.php?id=142
// So just do our own. (The const is entirely to humor the stupid compiler.)
int qstrcmp(const void *a, const void *b)
{
return strcmp(*(char **)a, *(char **)b);
}
// According to http://www.opengroup.org/onlinepubs/9629399/apdxa.htm
// we should generate a uuid structure by reading a clock with 100 nanosecond
// precision, normalizing it to the start of the gregorian calendar in 1582,
// and looking up our eth0 mac address.
//
// On the other hand, we have 128 bits to come up with a unique identifier, of
// which 6 have a defined value. /dev/urandom it is.
void create_uuid(char *uuid)
{
// Read 128 random bits
int fd = xopen("/dev/urandom", O_RDONLY);
xreadall(fd, uuid, 16);
close(fd);
// Claim to be a DCE format UUID.
uuid[6] = (uuid[6] & 0x0F) | 0x40;
uuid[8] = (uuid[8] & 0x3F) | 0x80;
// rfc2518 section 6.4.1 suggests if we're not using a macaddr, we should
// set bit 1 of the node ID, which is the mac multicast bit. This means we
// should never collide with anybody actually using a macaddr.
uuid[11] |= 128;
}
char *show_uuid(char *uuid)
{
char *out = libbuf;
int i;
for (i=0; i<16; i++) out+=sprintf(out, "-%02x"+!(0x550&(1<<i)), uuid[i]);
*out = 0;
return libbuf;
}
// Returns pointer to letter at end, 0 if none. *start = initial %
char *next_printf(char *s, char **start)
{
for (; *s; s++) {
if (*s != '%') continue;
if (*++s == '%') continue;
if (start) *start = s-1;
while (0 <= stridx("0'#-+ ", *s)) s++;
while (isdigit(*s)) s++;
if (*s == '.') s++;
while (isdigit(*s)) s++;
return s;
}
return 0;
}
// Posix inexplicably hasn't got this, so find str in line.
char *strnstr(char *line, char *str)
{
long len = strlen(str);
char *s;
for (s = line; *s; s++) if (!strncasecmp(s, str, len)) break;
return *s ? s : 0;
}