roadmap: describe glibc commands.

Some glibc commands are irrelevant because they're for functionality
that is excluded from musl (mtrace, rpc*, localedef, iconvconfig, nscd).
getconf and catchsegv look like candidates for the development toolchain;
locale and iconv were already triaged.
getent is pretty lame, but it and the timezone stuff (tzselect zic
zdump) are the only new possibly interesting commands.

3 files changed, 185 insertions, 87 deletions

diff --git a/toys/posix/date.c b/toys/posix/date.c
index e1ba636d..a4e5e27c 100644
--- a/toys/posix/date.c
+++ b/toys/posix/date.c
@@ -7,21 +7,39 @@
  * Note: setting a 2 year date is 50 years back/forward from today,
  * not posix's hardwired magic dates.
 
-USE_DATE(NEWTOY(date, "r:u", TOYFLAG_BIN))
+USE_DATE(NEWTOY(date, "d:s:r:u", TOYFLAG_BIN))
 
 config DATE
   bool "date"
   default y
   help
-    usage: date [-u] [-r FILE] [+FORMAT] | mmddhhmm[[cc]yy[.ss]]
+    usage: date [-u] [-r FILE] [-d DATE] [+DISPLAY_FORMAT] [-s SET_FORMAT] [SET]
 
-    Set/get the current date/time.
+    Set/get the current date/time. With no SET shows the current date.
 
-    Setting the date requires month, day, hour (0-23), and minute, each
-    two digits. It can optionally include year, century, and .seconds.
+    Default SET format is "MMDDhhmm[[CC]YY][.ss]", that's (2 digits each)
+    month, day, hour (0-23), and minute. Optionally century, year, and second.
 
-    -u	Use UTC timezone instead of current
-    -r	Use date from FILE instead of current date
+    -d	Show DATE instead of current time (convert date format)
+    -r	Use modification time of FILE instead of current date
+    -s	+FORMAT for SET or -d (instead of MMDDhhmm[[CC]YY][.ss])
+    -u	Use UTC instead of current timezone
+
+    +FORMAT specifies display format string using these escapes:
+
+    %% literal %             %n newline              %t tab
+    %S seconds (00-60)       %M minute (00-59)       %m month (01-12)
+    %H hour (0-23)           %I hour (01-12)         %p AM/PM
+    %y short year (00-99)    %Y year                 %C century
+    %a short weekday name    %A weekday name         %u day of week (1-7, 1=mon)
+    %b short month name      %B month name           %Z timezone name
+    %j day of year (001-366) %d day of month (01-31) %e day of month ( 1-31)
+
+    %U Week of year (0-53 start sunday)   %W Week of year (0-53 start monday)
+    %V Week of year (1-53 start monday, week < 4 days not part of this year) 
+
+    %D = "%m/%d/%y"    %r = "%I : %M : %S %p"   %T = "%H:%M:%S"   %h = "%b"
+    %x locale date     %X locale time           %c locale date/time
 */
 
 #define FOR_date
@@ -29,72 +47,95 @@ config DATE
 
 GLOBALS(
   char *file;
+  char *setfmt;
+  char *showdate;
 )
 
+// Handle default posix date format: mmddhhmm[[cc]yy]
+// returns 0 success, nonzero for error
+int parse_posixdate(char *str, struct tm *tm)
+{
+  struct timeval tv;
+  int len;
+
+  len = 0;
+  sscanf(str, "%2u%2u%2u%2u%n", &tm.tm_mon, &tm.tm_mday, &tm.tm_hour,
+    &tm.tm_min, &len);
+  if (len != 8) goto bad_date;
+  str += len;
+  tm.tm_mon--;
+
+  // If year specified, overwrite one we fetched earlier
+  if (*str && *str != '.') {
+    unsigned year, r1 = tm.tm_year % 100, r2 = (tm.tm_year + 50) % 100,
+      century = tm.tm_year - r1;
+
+    len = 0;
+    sscanf(str, "%u%n", &year, &len);
+    if (len == 4) year -= 1900;
+    else if (len != 2) goto bad_date;
+    str += len;
+
+    // 2 digit years, next 50 years are "future", last 50 years are "past".
+    // A "future" date in past is a century ahead.
+    // A non-future date in the future is a century behind.
+    if ((r1 < r2) ? (r1 < year && year < r2) : (year < r1 || year > r2)) {
+      if (year < r1) year += 100;
+    } else if (year > r1) year -= 100;
+    tm.tm_year = year + century;
+  }
+  if (*str == '.') {
+    len = 0;
+    sscanf(str, ".%u%n", &tm.tm_sec, &len);
+    str += len;
+  }
+
+  return *str;
+}
+
+
 void date_main(void)
 {
-  const char *format_string = "%a %b %e %H:%M:%S %Z %Y";
+  char *setdate = *toys.optargs, *format_string = "%a %b %e %H:%M:%S %Z %Y",
+       *tz;
   time_t now = time(NULL);
   struct tm tm;
 
+  // We can't just pass a timezone to mktime because posix.
+  if (toys.optflags & FLAG_u) {
+    tz = CFG_TOYBOX_FREE ? getenv("TZ") : 0;
+    setenv("TZ", "UTC", 1);
+    tzset();
+  }
+
   if (TT.file) {
     struct stat st;
 
     xstat(TT.file, &st);
     now = st.st_mtim.tv_sec;
-  }
-  ((toys.optflags & FLAG_u) ? gmtime_r : localtime_r)(&now, &tm);
+  } else if (TT.showdate) {
+    if (TT.setfmt) {
+      char *s = strptime(TT.showdate, TT.setfmt, &tm);
 
-  // Display the date?
-  if (!toys.optargs[0] || toys.optargs[0][0] == '+') {
-    if (toys.optargs[0]) format_string = toys.optargs[0]+1;
-    if (!strftime(toybuf, sizeof(toybuf), format_string, &tm)) goto bad_format;
+      if (!s || !*s) goto bad_date;
+    } else if (parse_posixdate(TT.showdate, &tm)) goto bad_date;
+  } else localtime_r(&now, &tm);
 
-    puts(toybuf);
+  // Fall through if no arguments
+  if (!setdate);
+  // Display the date?
+  else if (*setdate == '+') {
+    format_string = toys.optargs[0]+1;
+    setdate = toys.optargs[1];
 
   // Set the date
-  } else {
-    struct timeval tv;
-    char *s = *toys.optargs;
-    int len;
-
-    // Date format: mmddhhmm[[cc]yy]
-    len = 0;
-    sscanf(s, "%2u%2u%2u%2u%n", &tm.tm_mon, &tm.tm_mday, &tm.tm_hour,
-      &tm.tm_min, &len);
-    if (len != 8) goto bad_date;
-    s += len;
-    tm.tm_mon--;
-
-    // If year specified, overwrite one we fetched earlier
-    if (*s && *s != '.') {
-      unsigned year, r1 = tm.tm_year % 100, r2 = (tm.tm_year + 50) % 100,
-        century = tm.tm_year - r1;
-
-      len = 0;
-      sscanf(s, "%u%n", &year, &len);
-      if (len == 4) year -= 1900;
-      else if (len != 2) goto bad_date;
-      s += len;
-
-      // 2 digit years, next 50 years are "future", last 50 years are "past".
-      // A "future" date in past is a century ahead.
-      // A non-future date in the future is a century behind.
-      if ((r1 < r2) ? (r1 < year && year < r2) : (year < r1 || year > r2)) {
-        if (year < r1) year += 100;
-      } else if (year > r1) year -= 100;
-      tm.tm_year = year + century;
-    }
-    if (*s == '.') {
-      len = 0;
-      sscanf(s, ".%u%n", &tm.tm_sec, &len);
-      s += len;
-    }
-    if (*s) goto bad_date;
+  } else if (setdate) {
+    if (parse_posixdate(setdate, tm)) goto bad_date;
 
     if (toys.optflags & FLAG_u) {
-      // Get the UTC version of a struct tm
+      // We can't just pass a timezone to mktime because posix.
       char *tz = CFG_TOYBOX_FREE ? getenv("TZ") : 0;
+
       setenv("TZ", "UTC", 1);
       tzset();
       tv.tv_sec = mktime(&tm);
@@ -107,11 +148,18 @@ void date_main(void)
     if (tv.tv_sec == (time_t)-1) goto bad_date;
 
     tv.tv_usec = 0;
-    if (!strftime(toybuf, sizeof(toybuf), format_string, &tm)) goto bad_format;
-    puts(toybuf);
     if (settimeofday(&tv, NULL) < 0) perror_msg("cannot set date");
   }
 
+  if (toys.optflags & FLAG_u) {
+    if (tz) setenv("TZ", tz, 1);
+    else unsetenv("TZ");
+    tzset();
+  }
+
+  if (!strftime(toybuf, sizeof(toybuf), format_string, &tm)) goto bad_format;
+  puts(toybuf);
+
   return;
 
 bad_date:
diff --git a/toys/posix/du.c b/toys/posix/du.c
index 96922bca..64ba0517 100644
--- a/toys/posix/du.c
+++ b/toys/posix/du.c
@@ -54,18 +54,8 @@ static void print(long long size, struct dirtree *node)
 
   if (TT.maxdepth && TT.depth > TT.maxdepth) return;
 
-  if (toys.optflags & FLAG_h) {
-    char buf[32];
-    int index, sz;
-
-    for (index = 0; 1024 < size>>(10*index); index++);
-    sz = size>>(10*index);
-    if (sz < 10) {
-      sprintf(buf, "%llu", size>>(10*(index-1)));
-      printf("%c.%c", buf[0], buf[1]);
-    } else printf("%d", sz);
-    if (index) printf("%c", " KMGTPE"[index]);
-  } else {
+  if (toys.optflags & FLAG_h) printf("%s", human_readable(size));
+  else {
     int bits = 10;
 
     if (toys.optflags & FLAG_K) bits = 9;
diff --git a/toys/posix/grep.c b/toys/posix/grep.c
index aba70878..2837cc24 100644
--- a/toys/posix/grep.c
+++ b/toys/posix/grep.c
@@ -4,7 +4,7 @@
  *
  * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/grep.html
 
-USE_GREP(NEWTOY(grep, "ZzEFHabhinorsvwclqe*f*m#x[!wx][!EFw]", TOYFLAG_BIN))
+USE_GREP(NEWTOY(grep, "A#B#C#ZzEFHabhinorsvwclqe*f*m#x[!wx][!EFw]", TOYFLAG_BIN))
 USE_GREP(OLDTOY(egrep, grep, OPTSTR_grep, TOYFLAG_BIN))
 USE_GREP(OLDTOY(fgrep, grep, OPTSTR_grep, TOYFLAG_BIN))
 
@@ -46,40 +46,67 @@ GLOBALS(
   long m;
   struct arg_list *f;
   struct arg_list *e;
+  long C;
+  long B;
+  long A;
 
   struct arg_list *regex;
+  struct double_list *blist;
 )
 
+struct dlist_off {
+  char *next, *prev;
+  long offset;
+  char *data;
+};
+
 static void do_grep(int fd, char *name)
 {
   FILE *file = fdopen(fd, "r");
   long offset = 0;
-  int lcount = 0, mcount = 0, which = toys.optflags & FLAG_w ? 2 : 0;
+  int lcount = 0, mcount = 0, which = toys.optflags & FLAG_w ? 2 : 0,
+      blines = 0, alines = 0, dash = 0;
   char indelim = '\n' * !(toys.optflags&FLAG_z),
        outdelim = '\n' * !(toys.optflags&FLAG_Z);
 
   if (!fd) name = "(standard input)";
 
+fprintf(stderr, "boo\n");
   if (!file) {
     perror_msg("%s", name);
     return;
   }
 
+  // Loop through lines of input
   for (;;) {
-    char *line = 0, *start;
+    char *oline = 0, *line = 0, *start;
     regmatch_t matches[3];
     size_t unused;
     long len;
     int mmatch = 0;
 
+    // Read next line of input
     lcount++;
     if (0 > (len = getdelim(&line, &unused, indelim, file))) break;
     if (line[len-1] == indelim) line[len-1] = 0;
+fprintf(stderr, "line=%s\n", line);
+    // Unconditionally add line to blist so output can always just dump blist.
+    dlist_add(&TT.blist, line);
+fprintf(stderr, "added=%s\n", TT.blist->data);
+fprintf(stderr, "prev=%s\n", TT.blist->prev->data);
+    if (blines <= TT.B) blines++;
+    else {
+      struct double_list *temp = dlist_pop(&TT.blist);
+fprintf(stderr, "bird=%s\n", temp->data);
+      free(temp->data);
+      free(temp);
+    }
 
     start = line;
 
-    for (;;)
-    {
+    // Loop to match multiple times within the same line (if necessary)
+    for (;;) {
+fprintf(stderr, "match?\n");
       int rc = 0, skip = 0;
 
       if (toys.optflags & FLAG_F) {
@@ -132,30 +159,51 @@ static void do_grep(int fd, char *name)
         }
         matches[which].rm_so = 0;
       } else if (rc) break;
-
+fprintf(stderr, "got match %s\n", line);
+      // We got a match, figure out how to display it
       mmatch++;
       toys.exitval = 0;
       if (toys.optflags & FLAG_q) xexit();
       if (toys.optflags & FLAG_l) {
         printf("%s%c", name, outdelim);
-        free(line);
-        fclose(file);
-        return;
+        goto finish;
       }
+
+      line = 0;
+fprintf(stderr, "here=%s\n", TT.blist->prev->data);
+      // Yes, -o sometimes counts things as a match (-c) but doesn't display it
       if (toys.optflags & FLAG_o)
         if (matches[which].rm_eo == matches[which].rm_so)
           break;
 
-      if (!(toys.optflags & FLAG_c)) {
-        if (toys.optflags & FLAG_H) printf("%s:", name);
-        if (toys.optflags & FLAG_n) printf("%d:", lcount);
-        if (toys.optflags & FLAG_b)
-          printf("%ld:", offset + (start-line) +
-              ((toys.optflags & FLAG_o) ? matches[which].rm_so : 0));
-        if (!(toys.optflags & FLAG_o)) xprintf("%s%c", line, outdelim);
+// List of lines that DIDN'T match, print backlog?
+// Except this includes the one we just matched...?
+      while (TT.blist) {
+        struct double_list *dlist = dlist_pop(&TT.blist);
+        char *ll = dlist->data;
+fprintf(stderr, "popped %s\n", ll);
+        if (dash) printf("--%c", outdelim);
+        dash = 0;
+
+        if (!(toys.optflags & FLAG_c)) {
+          if (toys.optflags & FLAG_H) printf("%s:", name);
+          if (toys.optflags & FLAG_n) printf("%d:", lcount);
+          if (toys.optflags & FLAG_b)
+            printf("%ld:", offset + (start - dlist->data) +
+                ((toys.optflags & FLAG_o) ? matches[which].rm_so : 0));
+          if (!(toys.optflags & FLAG_o)) xprintf("%s%c", dlist->data, outdelim);
+          else if (!TT.blist) {
+
+// TODO: FLAG_o prints multiple times, can't free it yet?
+            xprintf("%.*s%c", matches[which].rm_eo - matches[which].rm_so,
+                    start + matches[which].rm_so, outdelim);
+            line = dlist->data;
+          }
+        }
+        if (oline && !TT.blist) TT.blist = dlist;
         else {
-          xprintf("%.*s%c", matches[which].rm_eo - matches[which].rm_so,
-                  start + matches[which].rm_so, outdelim);
+          free(dlist->data);
+          free(dlist);
         }
       }
 
@@ -163,7 +211,7 @@ static void do_grep(int fd, char *name)
       if (!(toys.optflags & FLAG_o) || !*start) break;
     }
     offset += len;
-
+fprintf(stderr, "Spacious skies\n");
     free(line);
 
     if (mmatch) mcount++;
@@ -175,6 +223,14 @@ static void do_grep(int fd, char *name)
     xprintf("%d%c", mcount, outdelim);
   }
 
+finish:
+  while (CFG_TOYBOX_FREE && TT.blist) {
+    struct double_list *dlist = dlist_pop(&TT.blist);
+
+    free(dlist->data);
+    free(dlist);
+  }
+
   // loopfiles will also close the fd, but this frees an (opaque) struct.
   fclose(file);
 }
@@ -273,6 +329,10 @@ void grep_main(void)
     toys.optc--;
   }
 
+  if (!TT.A) TT.A = TT.C;
+  if (!TT.B) TT.B = TT.C;
+  if (toys.optflags & (FLAG_l|FLAG_o)) TT.B = 0; // avoid memory leak
+
   parse_regex();
 
   if (!(toys.optflags & FLAG_h) && toys.optc>1) toys.optflags |= FLAG_H;