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[apt.git] / apt-pkg / contrib / strutl.cc

// -*- mode: cpp; mode: fold -*-
// Description								/*{{{*/
// $Id: strutl.cc,v 1.7 1998/10/23 00:49:59 jgg Exp $
/* ######################################################################

   String Util - Some usefull string functions.

   These have been collected from here and there to do all sorts of usefull
   things to strings. They are usefull in file parsers, URI handlers and
   especially in APT methods.   
   
   This source is placed in the Public Domain, do with it what you will
   It was originally written by Jason Gunthorpe <jgg@gpu.srv.ualberta.ca>
   
   ##################################################################### */
									/*}}}*/
// Includes								/*{{{*/
#include <strutl.h>
#include <apt-pkg/fileutl.h>

#include <ctype.h>
#include <string.h>
#include <stdio.h>
#include <time.h>
									/*}}}*/

// strstrip - Remove white space from the front and back of a string	/*{{{*/
// ---------------------------------------------------------------------
/* This is handy to use when parsing a file. It also removes \n's left 
   over from fgets and company */
char *_strstrip(char *String)
{
   for (;*String != 0 && (*String == ' ' || *String == '\t'); String++);

   if (*String == 0)
      return String;

   char *End = String + strlen(String) - 1;
   for (;End != String - 1 && (*End == ' ' || *End == '\t' || *End == '\n' ||
			       *End == '\r'); End--);
   End++;
   *End = 0;
   return String;
};
									/*}}}*/
// strtabexpand - Converts tabs into 8 spaces				/*{{{*/
// ---------------------------------------------------------------------
/* */
char *_strtabexpand(char *String,size_t Len)
{
   for (char *I = String; I != I + Len && *I != 0; I++)
   {
      if (*I != '\t')
	 continue;
      if (I + 8 > String + Len)
      {
	 *I = 0;
	 return String;
      }

      /* Assume the start of the string is 0 and find the next 8 char
         division */
      int Len;
      if (String == I)
	 Len = 1;
      else
	 Len = 8 - ((String - I) % 8);
      Len -= 2;
      if (Len <= 0)
      {
	 *I = ' ';
	 continue;
      }
      
      memmove(I + Len,I + 1,strlen(I) + 1);
      for (char *J = I; J + Len != I; *I = ' ', I++);
   }
   return String;
}
									/*}}}*/
// ParseQuoteWord - Parse a single word out of a string			/*{{{*/
// ---------------------------------------------------------------------
/* This grabs a single word, converts any % escaped characters to their
   proper values and advances the pointer. Double quotes are understood
   and striped out as well. This is for URI/URL parsing. */
bool ParseQuoteWord(const char *&String,string &Res)
{
   // Skip leading whitespace
   const char *C = String;
   for (;*C != 0 && *C == ' '; C++);
   if (*C == 0)
      return false;
   
   // Jump to the next word
   for (;*C != 0 && *C != ' '; C++)
   {
      if (*C == '"')
      {
	 for (C++;*C != 0 && *C != '"'; C++);
	 if (*C == 0)
	    return false;
      }
   }

   // Now de-quote characters
   char Buffer[1024];
   char Tmp[3];
   const char *Start = String;
   char *I;
   for (I = Buffer; I < Buffer + sizeof(Buffer) && Start != C; I++)
   {
      if (*Start == '%' && Start + 2 < C)
      {
	 Tmp[0] = Start[1];
	 Tmp[1] = Start[2];
	 Tmp[3] = 0;
	 *I = (char)strtol(Tmp,0,16);
	 Start += 3;
	 continue;
      }
      if (*Start != '"')
	 *I = *Start;
      else
	 I--;
      Start++;
   }
   *I = 0;
   Res = Buffer;
   
   // Skip ending white space
   for (;*C != 0 && *C == ' '; C++);
   String = C;
   return true;
}
									/*}}}*/
// ParseCWord - Parses a string like a C "" expression			/*{{{*/
// ---------------------------------------------------------------------
/* This expects a series of space seperated strings enclosed in ""'s. 
   It concatenates the ""'s into a single string. */
bool ParseCWord(const char *String,string &Res)
{
   // Skip leading whitespace
   const char *C = String;
   for (;*C != 0 && *C == ' '; C++);
   if (*C == 0)
      return false;
   
   char Buffer[1024];
   char *Buf = Buffer;
   if (strlen(String) >= sizeof(Buffer))
       return false;
       
   for (; *C != 0; C++)
   {
      if (*C == '"')
      {
	 for (C++; *C != 0 && *C != '"'; C++)
	    *Buf++ = *C;
	 
	 if (*C == 0)
	    return false;
	 
	 continue;
      }      
      
      if (C != String && isspace(*C) != 0 && isspace(C[-1]) != 0)
	 continue;
      if (isspace(*C) == 0)
	 return false;
      *Buf++ = ' ';
   }   
   *Buf = 0;
   Res = Buffer;
   return true;
}
									/*}}}*/
// QuoteString - Convert a string into quoted from			/*{{{*/
// ---------------------------------------------------------------------
/* */
string QuoteString(string Str,const char *Bad)
{
   string Res;
   for (string::iterator I = Str.begin(); I != Str.end(); I++)
   {
      if (strchr(Bad,*I) != 0 || isprint(*I) == 0 || 
	  *I <= 0x20 || *I >= 0x7F)
      {
	 char Buf[10];
	 sprintf(Buf,"%%%02x",(int)*I);
	 Res += Buf;
      }
      else
	 Res += *I;
   }
   return Res;
}
									/*}}}*/
// SizeToStr - Convert a long into a human readable size		/*{{{*/
// ---------------------------------------------------------------------
/* A max of 4 digits are shown before conversion to the next highest unit. 
   The max length of the string will be 5 chars unless the size is > 10
   YottaBytes (E24) */
string SizeToStr(double Size)
{
   char S[300];
   double ASize;
   if (Size >= 0)
      ASize = Size;
   else
      ASize = -1*Size;
   
   /* bytes, KiloBytes, MegaBytes, GigaBytes, TeraBytes, PetaBytes, 
      ExaBytes, ZettaBytes, YottaBytes */
   char Ext[] = {'b','k','M','G','T','P','E','Z','Y'};
   int I = 0;
   while (I <= 8)
   {
      if (ASize < 100 && I != 0)
      {
         sprintf(S,"%.1f%c",ASize,Ext[I]);
	 break;
      }
      
      if (ASize < 10000)
      {
         sprintf(S,"%.0f%c",ASize,Ext[I]);
	 break;
      }
      ASize /= 1000.0;
      I++;
   }
   
   return S;
}
									/*}}}*/
// TimeToStr - Convert the time into a string				/*{{{*/
// ---------------------------------------------------------------------
/* Converts a number of seconds to a hms format */
string TimeToStr(unsigned long Sec)
{
   char S[300];
   
   while (1)
   {
      if (Sec > 60*60*24)
      {
	 sprintf(S,"%lid %lih%lim%lis",Sec/60/60/24,(Sec/60/60) % 24,(Sec/60) % 60,Sec % 60);
	 break;
      }
      
      if (Sec > 60*60)
      {
	 sprintf(S,"%lih%lim%lis",Sec/60/60,(Sec/60) % 60,Sec % 60);
	 break;
      }
      
      if (Sec > 60)
      {
	 sprintf(S,"%lim%lis",Sec/60,Sec % 60);
	 break;
      }
      
      sprintf(S,"%lis",Sec);
      break;
   }
   
   return S;
}
									/*}}}*/
// SubstVar - Substitute a string for another string			/*{{{*/
// ---------------------------------------------------------------------
/* This replaces all occurances of Subst with Contents in Str. */
string SubstVar(string Str,string Subst,string Contents)
{
   string::size_type Pos = 0;
   string::size_type OldPos = 0;
   string Temp;
   
   while (OldPos < Str.length() && 
	  (Pos = Str.find(Subst,OldPos)) != string::npos)
   {
      Temp += string(Str,OldPos,Pos) + Contents;
      OldPos = Pos + Subst.length();      
   }
   
   if (OldPos == 0)
      return Str;
   
   return Temp + string(Str,OldPos);
}
									/*}}}*/
// URItoFileName - Convert the uri into a unique file name		/*{{{*/
// ---------------------------------------------------------------------
/* This converts a URI into a safe filename. It quotes all unsafe characters
   and converts / to _ and removes the scheme identifier. The resulting
   file name should be unique and never occur again for a different file */
string URItoFileName(string URI)
{
   string::const_iterator I = URI.begin() + URI.find(':') + 1;
   for (; I < URI.end() && *I == '/'; I++);

   // "\x00-\x20{}|\\\\^\\[\\]<>\"\x7F-\xFF";
   URI = QuoteString(string(I,URI.end() - I),"\\|{}[]<>\"^~_=!@#$%^&*");
   string::iterator J = URI.begin();
   for (; J != URI.end(); J++)
      if (*J == '/') 
	 *J = '_';
   return URI;
}
									/*}}}*/
// URIAccess - Return the access method for the URI			/*{{{*/
// ---------------------------------------------------------------------
/* */
string URIAccess(string URI)
{
   string::size_type Pos = URI.find(':');
   if (Pos == string::npos)
      return URI;
   return string(URI,0,Pos);
}
									/*}}}*/
// Base64Encode - Base64 Encoding routine for short strings		/*{{{*/
// ---------------------------------------------------------------------
/* This routine performs a base64 transformation on a string. It was ripped
   from wget and then patched and bug fixed.
 
   This spec can be found in rfc2045 */
string Base64Encode(string S)
{
   // Conversion table.
   static char tbl[64] = {'A','B','C','D','E','F','G','H',
   			  'I','J','K','L','M','N','O','P',
                          'Q','R','S','T','U','V','W','X',
                          'Y','Z','a','b','c','d','e','f',
                          'g','h','i','j','k','l','m','n',
                          'o','p','q','r','s','t','u','v',
                          'w','x','y','z','0','1','2','3',
                          '4','5','6','7','8','9','+','/'};
   
   // Pre-allocate some space
   string Final;
   Final.reserve((4*S.length() + 2)/3 + 2);

   /* Transform the 3x8 bits to 4x6 bits, as required by
      base64.  */
   for (string::const_iterator I = S.begin(); I < S.end(); I += 3)
   {
      char Bits[3] = {0,0,0};
      Bits[0] = I[0];
      if (I + 1 < S.end())
	 Bits[1] = I[1];
      if (I + 2 < S.end())
	 Bits[2] = I[2];

      Final += tbl[Bits[0] >> 2];
      Final += tbl[((Bits[0] & 3) << 4) + (Bits[1] >> 4)];
      
      if (I + 1 >= S.end())
	 break;
      
      Final += tbl[((Bits[1] & 0xf) << 2) + (Bits[2] >> 6)];
      
      if (I + 2 >= S.end())
	 break;
      
      Final += tbl[Bits[2] & 0x3f];
   }

   /* Apply the padding elements, this tells how many bytes the remote
      end should discard */
   if (S.length() % 3 == 2)
      Final += '=';
   if (S.length() % 3 == 1)
      Final += "==";
   
   return Final;
}
									/*}}}*/
// stringcmp - Arbitary string compare					/*{{{*/
// ---------------------------------------------------------------------
/* This safely compares two non-null terminated strings of arbitary 
   length */
int stringcmp(const char *A,const char *AEnd,const char *B,const char *BEnd)
{
   for (; A != AEnd && B != BEnd; A++, B++)
      if (*A != *B)
	 break;
   
   if (A == AEnd && B == BEnd)
      return 0;
   if (A == AEnd)
      return 1;
   if (B == BEnd)
      return -1;
   if (*A < *B)
      return -1;
   return 1;
}
									/*}}}*/
// stringcasecmp - Arbitary case insensitive string compare		/*{{{*/
// ---------------------------------------------------------------------
/* */
int stringcasecmp(const char *A,const char *AEnd,const char *B,const char *BEnd)
{
   for (; A != AEnd && B != BEnd; A++, B++)
      if (toupper(*A) != toupper(*B))
	 break;

   if (A == AEnd && B == BEnd)
      return 0;
   if (A == AEnd)
      return 1;
   if (B == BEnd)
      return -1;
   if (toupper(*A) < toupper(*B))
      return -1;
   return 1;
}
									/*}}}*/
// LookupTag - Lookup the value of a tag in a taged string		/*{{{*/
// ---------------------------------------------------------------------
/* The format is like those used in package files and the method 
   communication system */
string LookupTag(string Message,const char *Tag,const char *Default)
{
   // Look for a matching tag.
   int Length = strlen(Tag);
   for (string::iterator I = Message.begin(); I + Length < Message.end(); I++)
   {
      // Found the tag
      if (I[Length] == ':' && stringcasecmp(I,I+Length,Tag) == 0)
      {
	 // Find the end of line and strip the leading/trailing spaces
	 string::iterator J;
	 I += Length + 1;
	 for (; isspace(*I) != 0 && I < Message.end(); I++);
	 for (J = I; *J != '\n' && J < Message.end(); J++);
	 for (; J > I && isspace(J[-1]) != 0; J--);
	 
	 return string(I,J-I);
      }
      
      for (; *I != '\n' && I < Message.end(); I++);
   }   
   
   // Failed to find a match
   if (Default == 0)
      return string();
   return Default;
}
									/*}}}*/
// StringToBool - Converts a string into a boolean			/*{{{*/
// ---------------------------------------------------------------------
/* This inspects the string to see if it is true or if it is false and
   then returns the result. Several varients on true/false are checked. */
int StringToBool(string Text,int Default = -1)
{
   char *End;
   int Res = strtol(Text.c_str(),&End,0);   
   if (End != Text.c_str() && Res >= 0 && Res <= 1)
      return Res;
   
   // Check for positives
   if (strcasecmp(Text.c_str(),"no") == 0 ||
       strcasecmp(Text.c_str(),"false") == 0 ||
       strcasecmp(Text.c_str(),"without") == 0 ||
       strcasecmp(Text.c_str(),"disable") == 0)
      return 0;
   
   // Check for negatives
   if (strcasecmp(Text.c_str(),"yes") == 0 ||
       strcasecmp(Text.c_str(),"true") == 0 ||
       strcasecmp(Text.c_str(),"with") == 0 ||
       strcasecmp(Text.c_str(),"enable") == 0)
      return 1;
   
   return Default;
}
									/*}}}*/
// TimeRFC1123 - Convert a time_t into RFC1123 format			/*{{{*/
// ---------------------------------------------------------------------
/* This converts a time_t into a string time representation that is
   year 2000 complient and timezone neutral */
string TimeRFC1123(time_t Date)
{
   struct tm Conv = *gmtime(&Date);
   char Buf[300];

   const char *Day[] = {"Sun","Mon","Tue","Wed","Thu","Fri","Sat"};
   const char *Month[] = {"Jan","Feb","Mar","Apr","May","Jun","Jul",
                          "Aug","Sep","Oct","Nov","Dec"};

   sprintf(Buf,"%s, %02i %s %i %02i:%02i:%02i GMT",Day[Conv.tm_wday],
	   Conv.tm_mday,Month[Conv.tm_mon],Conv.tm_year+1900,Conv.tm_hour,
	   Conv.tm_min,Conv.tm_sec);
   return Buf;
}
									/*}}}*/
// ReadMessages - Read messages from the FD				/*{{{*/
// ---------------------------------------------------------------------
/* This pulls full messages from the input FD into the message buffer. 
   It assumes that messages will not pause during transit so no
   fancy buffering is used. */
bool ReadMessages(int Fd, vector<string> &List)
{
   char Buffer[4000];
   char *End = Buffer;
   
   while (1)
   {
      int Res = read(Fd,End,sizeof(Buffer) - (End-Buffer));
      
      // Process is dead, this is kind of bad..
      if (Res == 0)
	 return false;
      
      // No data
      if (Res <= 0)
	 return true;

      End += Res;
      
      // Look for the end of the message
      for (char *I = Buffer; I < End; I++)
      {
	 if (I[0] != '\n' || I[1] != '\n')
	    continue;
	 
	 // Pull the message out
	 string Message(Buffer,0,I-Buffer);

	 // Fix up the buffer
	 for (; I < End && *I == '\n'; I++);
	 End -= I-Buffer;	 
	 memmove(Buffer,I,End-Buffer);
	 I = Buffer;
	 
	 List.push_back(Message);
      }
      if (End == Buffer)
	 return true;

      if (WaitFd(Fd) == false)
	 return false;
   }   
}
									/*}}}*/
// MonthConv - Converts a month string into a number			/*{{{*/
// ---------------------------------------------------------------------
/* This was lifted from the boa webserver which lifted it from 'wn-v1.07'
   Made it a bit more robust with a few touppers though. */
static int MonthConv(char *Month)
{
   switch (toupper(*Month)) 
   {
      case 'A':
      return toupper(Month[1]) == 'P'?3:7;
      case 'D':
      return 11;
      case 'F':
      return 1;
      case 'J':
      if (toupper(Month[1]) == 'A')
	 return 0;
      return toupper(Month[2]) == 'N'?5:6;
      case 'M':
      return toupper(Month[2]) == 'R'?2:4;
      case 'N':
      return 10;
      case 'O':
      return 9;
      case 'S':
      return 8;

      // Pretend it is January..
      default:
      return 0;
   }   
}
									/*}}}*/
// StrToTime - Converts a string into a time_t				/*{{{*/
// ---------------------------------------------------------------------
/* This handles all 3 populare time formats including RFC 1123, RFC 1036
   and the C library asctime format. It requires the GNU library function
   'timegm' to convert a struct tm in UTC to a time_t. For some bizzar
   reason the C library does not provide any such function :<*/
bool StrToTime(string Val,time_t &Result)
{
   struct tm Tm;
   char Month[10];
   const char *I = Val.c_str();
   
   // Skip the day of the week
   for (;*I != 0  && *I != ' '; I++);
   
   // Handle RFC 1123 time
   if (sscanf(I," %d %3s %d %d:%d:%d GMT",&Tm.tm_mday,Month,&Tm.tm_year,
	      &Tm.tm_hour,&Tm.tm_min,&Tm.tm_sec) != 6)
   {
      // Handle RFC 1036 time
      if (sscanf(I," %d-%3s-%d %d:%d:%d GMT",&Tm.tm_mday,Month,
		 &Tm.tm_year,&Tm.tm_hour,&Tm.tm_min,&Tm.tm_sec) == 6)
	 Tm.tm_year += 1900;
      else
      {
	 // asctime format
	 if (sscanf(I," %3s %d %d:%d:%d %d",Month,&Tm.tm_mday,
		    &Tm.tm_hour,&Tm.tm_min,&Tm.tm_sec,&Tm.tm_year) != 6)
	    return false;
      }
   }
   
   Tm.tm_isdst = 0;
   Tm.tm_mon = MonthConv(Month);
   Tm.tm_year -= 1900;
   
   // Convert to local time and then to GMT
   Result = timegm(&Tm);
   return true;
}
									/*}}}*/