add fmt_human, fmt_humank and fmt_httpdate

CHANGES

@@ -12,6 +12,7 @@
   add stralloc versions of textcode API (Kai Ruemmler)
   add html to textcode ('<' to '&lt;' etc)
   add fmt_human and fmt_humank (format numbers ala ls -H/-h)
+  add fmt_httpdate
 
 0.14:
   avoid bus errors in byte_copy

fmt.h

@@ -1,6 +1,9 @@
 #ifndef FMT_H
 #define FMT_H
 
+/* for time_t: */
+#include <sys/types.h>
+
 #define FMT_LONG  41 /* enough space to hold -2^127 in decimal, plus \0 */
 #define FMT_ULONG 40 /* enough space to hold 2^128 - 1 in decimal, plus \0 */
 #define FMT_8LONG 44 /* enough space to hold 2^128 - 1 in octal, plus \0 */
@@ -75,4 +78,7 @@ unsigned int fmt_human(char* dest,unsigned long long l);
 /* 1 -> "1", 4900 -> "4.8k", 2300000 -> "2.2M" */
 unsigned int fmt_humank(char* dest,unsigned long long l);
 
+/* "Sun, 06 Nov 1994 08:49:37 GMT" */
+unsigned int fmt_httpdate(char* dest,time_t t);
+
 #endif

fmt/fmt_httpdate.3

@@ -0,0 +1,17 @@
+.TH fmt_httpdate 3
+.SH NAME
+fmt_httpdate \- write a date in ASCII as in the HTTP protocol
+.SH SYNTAX
+.B #include <fmt.h>
+
+unsigned int \fBfmt_httpdate\fP(char *\fIdest\fR,time_t \fIsource\fR);
+.SH DESCRIPTION
+fmt_httpdate writes a date in ASCII representation as the HTTP protocol defines it:
+"Sun, 06 Nov 1994 08:49:37 GMT".
+
+fmt_httpdate does not append \\0.
+
+If \fIdest\fR equals FMT_LEN (i.e. is zero), fmt_httpdate returns the number
+of bytes it would have written.
+
+The output of fmt_httpdate is 29 until Jan 1st 10000.

fmt/fmt_httpdate.c

@@ -0,0 +1,35 @@
+#include "fmt.h"
+#include "byte.h"
+#include <time.h>
+
+static unsigned int fmt_2digits(char* dest,int i) {
+  dest[0]=(i/10)+'0';
+  dest[1]=(i%10)+'0';
+  return 2;
+}
+
+unsigned int fmt_httpdate(char* dest,time_t t) {
+  static const char days[] = "SunMonTueWedThuFriSat";
+  static const char months[] = "JanFebMarAprMayJunJulAugSepOctNovDec";
+  struct tm* x=gmtime(&t);
+  int i;
+
+  if (dest==0) return 29;
+  /* "Sun, 06 Nov 1994 08:49:37 GMT" */
+  byte_copy(dest,3,days+3*x->tm_wday); i=3;
+  i+=fmt_str(dest+i,", ");
+  i+=fmt_2digits(dest+i,x->tm_mday);
+  i+=fmt_str(dest+i," ");
+  byte_copy(dest+i,3,months+3*x->tm_mon); i+=3;
+  i+=fmt_str(dest+i," ");
+  i+=fmt_2digits(dest+i,(x->tm_year+1900)/100);
+  i+=fmt_2digits(dest+i,(x->tm_year+1900)%100);
+  i+=fmt_str(dest+i," ");
+  i+=fmt_2digits(dest+i,x->tm_hour);
+  i+=fmt_str(dest+i,":");
+  i+=fmt_2digits(dest+i,x->tm_min);
+  i+=fmt_str(dest+i,":");
+  i+=fmt_2digits(dest+i,x->tm_sec);
+  i+=fmt_str(dest+i," GMT");
+  return i;
+}

fmt/fmt_human.3

@@ -0,0 +1,22 @@
+.TH fmt_human 3
+.SH NAME
+fmt_human \- write a human readable ASCII representation of a long integer
+.SH SYNTAX
+.B #include <fmt.h>
+
+unsigned int \fBfmt_human\fP(char *\fIdest\fR,unsigned long long \fIsource\fR);
+.SH DESCRIPTION
+fmt_human writes a human readable ASCII representation of \fIsource\fR
+to \fIdest\fR and returns the number of bytes written.  The result
+resembles the file size output of "ls -H"; 1000 becomes "1.0k", 1000000
+becomes "1.0M" and so on for "G" and "T".
+
+fmt_human does not append \\0.
+
+If \fIdest\fR equals FMT_LEN (i.e. is zero), fmt_human returns the number
+of bytes it would have written.
+
+The output of fmt_human can not exceed 11 (assuming unsigned long long
+has 64 bits).
+.SH "SEE ALSO"
+fmt_humank(3), scan_human(3)

fmt/fmt_human.c

@@ -5,7 +5,9 @@ unsigned int fmt_human(char* dest,unsigned long long l) {
   int i;
   if (l<1000) return fmt_ulong(dest,l);
   if (l>1000000000000ull) {
-    l=(l+50000000000ull)/100000000000ull;
+    /* dang!  overflow! */
+    l/=1000;
+    l=(l+50000000)/100000000;
     unit='T';
   } else if (l>1000000000) {
     l=(l+50000000)/100000000;
@@ -13,7 +15,7 @@ unsigned int fmt_human(char* dest,unsigned long long l) {
   } else if (l>1000000) {
     l=(l+50000)/100000;
     unit='M';
-  } else if (l>1000) {
+  } else {
     l=(l+50)/100;
     unit='k';
   }

fmt/fmt_humank.3

@@ -0,0 +1,22 @@
+.TH fmt_humank 3
+.SH NAME
+fmt_humank \- write a human readable ASCII representation of a long integer
+.SH SYNTAX
+.B #include <fmt.h>
+
+unsigned int \fBfmt_humank\fP(char *\fIdest\fR,unsigned long long \fIsource\fR);
+.SH DESCRIPTION
+fmt_humank writes a human readable ASCII representation of \fIsource\fR
+to \fIdest\fR and returns the number of bytes written.  The result
+resembles the file size output of "ls -h"; 1024 becomes "1.0k", 1048576
+becomes "1.0M" and so on for "G" and "T".
+
+fmt_humank does not append \\0.
+
+If \fIdest\fR equals FMT_LEN (i.e. is zero), fmt_humank returns the number
+of bytes it would have written.
+
+The output of fmt_humank can not exceed 11 (assuming unsigned long long
+has 64 bits).
+.SH "SEE ALSO"
+fmt_human(3), scan_humank(3)

fmt/fmt_humank.c

@@ -13,7 +13,7 @@ unsigned int fmt_humank(char* dest,unsigned long long l) {
   } else if (l>1024*1024) {
     l=(l+(1024*1024/20))/(1024*1024/10);
     unit='M';
-  } else if (l>1024) {
+  } else {
     l=(l+(1024/20))/(1024/10);
     unit='k';
   }

test/fmt_httpdate.c

@@ -0,0 +1,8 @@
+#include <time.h>
+#include <buffer.h>
+
+main() {
+  char buf[100];
+  buffer_put(buffer_1,buf,fmt_httpdate(buf,time(0)));
+  buffer_putnlflush(buffer_1);
+}

test/fmt_human.c

@@ -0,0 +1,10 @@
+#include <fmt.h>
+#include <buffer.h>
+
+main() {
+  char buf[1024];
+  buffer_put(buffer_1,buf,fmt_human(buf,1)); buffer_putnlflush(buffer_1);
+  buffer_put(buffer_1,buf,fmt_human(buf,1400)); buffer_putnlflush(buffer_1);
+  buffer_put(buffer_1,buf,fmt_human(buf,2300000)); buffer_putnlflush(buffer_1);
+  buffer_put(buffer_1,buf,fmt_human(buf,(unsigned long long)(-1ll))); buffer_putnlflush(buffer_1);
+}