memory leaks

This is a discussion on memory leaks within the C Programming forums, part of the General Programming Boards category; Hi, there's some memory errors (malloc?) with this application and I was wondering if anyone might know where the problem ...

  1. #1
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    Join Date
    Oct 2008
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    2

    Question memory leaks

    Hi, there's some memory errors (malloc?) with this application and I was wondering if anyone might know where the problem is and how to possibly fix it?

    The error:

    Code:
    *** glibc detected *** ./tur-ftpwho: corrupted double-linked list: 0x0000000000c82090 ***
    ======= Backtrace: =========
    /lib64/libc.so.6[0x3433278228]
    /lib64/libc.so.6[0x343327a638]
    /lib64/libc.so.6(cfree+0x76)[0x343327a866]
    ./tur-ftpwho[0x401a92]
    ./tur-ftpwho[0x4014ae]
    /lib64/libc.so.6(__libc_start_main+0xfa)[0x343321e32a]
    ./tur-ftpwho[0x400b39]
    ======= Memory map: ========
    00400000-00402000 r-xp 00000000 08:03 310097                             /root/tur-ftpwho
    00602000-00603000 rw-p 00002000 08:03 310097                             /root/tur-ftpwho
    00c82000-00ca3000 rw-p 00c82000 00:00 0                                  [heap]
    3432e00000-3432e1d000 r-xp 00000000 08:03 758906                         /lib64/ld-2.8.so
    343301c000-343301d000 r--p 0001c000 08:03 758906                         /lib64/ld-2.8.so
    343301d000-343301e000 rw-p 0001d000 08:03 758906                         /lib64/ld-2.8.so
    3433200000-3433362000 r-xp 00000000 08:03 758908                         /lib64/libc-2.8.so
    3433362000-3433562000 ---p 00162000 08:03 758908                         /lib64/libc-2.8.so
    3433562000-3433566000 r--p 00162000 08:03 758908                         /lib64/libc-2.8.so
    3433566000-3433567000 rw-p 00166000 08:03 758908                         /lib64/libc-2.8.so
    3433567000-343356c000 rw-p 3433567000 00:00 0
    3434a00000-3434a16000 r-xp 00000000 08:03 758999                         /lib64/libgcc_s-4.3.0-20080428.so.1
    3434a16000-3434c15000 ---p 00016000 08:03 758999                         /lib64/libgcc_s-4.3.0-20080428.so.1
    3434c15000-3434c16000 rw-p 00015000 08:03 758999                         /lib64/libgcc_s-4.3.0-20080428.so.1
    7fd974000000-7fd974021000 rw-p 7fd974000000 00:00 0
    7fd974021000-7fd978000000 ---p 7fd974021000 00:00 0
    7fd979c7c000-7fd979c7e000 rw-p 7fd979c7c000 00:00 0
    7fd979c8b000-7fd979c8d000 rw-p 7fd979c8b000 00:00 0
    7fff81c78000-7fff81c8d000 rw-p 7ffffffea000 00:00 0                      [stack]
    7fff81dff000-7fff81e00000 r-xp 7fff81dff000 00:00 0                      [vdso]
    ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]
    Aborted
    Here's a bit of valgrind:

    Code:
    ==18854== Memcheck, a memory error detector.
    ==18854== Copyright (C) 2002-2007, and GNU GPL'd, by Julian Seward et al.
    ==18854== Using LibVEX rev 1804, a library for dynamic binary translation.
    ==18854== Copyright (C) 2004-2007, and GNU GPL'd, by OpenWorks LLP.
    ==18854== Using valgrind-3.3.0, a dynamic binary instrumentation framework.
    ==18854== Copyright (C) 2000-2007, and GNU GPL'd, by Julian Seward et al.
    ==18854==
    --18854-- Command line
    --18854--    ./tur-ftpwho
    --18854-- Startup, with flags:
    --18854--    -v
    --18854-- Contents of /proc/version:
    --18854--   Linux version 2.6.25.3-18.fc9.x86_64 (mockbuild@) (gcc version 4.3.0 20080428 (Red Hat 4.3.0-8) (GCC) ) #1 SMP Tue May 13 04:54:47 EDT 2008
    --18854-- Arch and hwcaps: AMD64, amd64-sse2
    --18854-- Page sizes: currently 4096, max supported 4096
    --18854-- Valgrind library directory: /usr/lib64/valgrind
    --18854-- Reading syms from /root/tur-ftpwho (0x400000)
    --18854-- Reading syms from /usr/lib64/valgrind/amd64-linux/memcheck (0x38000000)
    --18854--    object doesn't have a dynamic symbol table
    --18854-- Reading syms from /lib64/ld-2.8.so (0x3432E00000)
    --18854-- Reading suppressions file: /usr/lib64/valgrind/default.supp
    --18854-- Reading syms from /usr/lib64/valgrind/amd64-linux/vgpreload_core.so (0x4802000)
    --18854-- Reading syms from /usr/lib64/valgrind/amd64-linux/vgpreload_memcheck.so (0x4A03000)
    --18854-- REDIR: 0x3432e16070 (index) redirected to 0x4a07890 (index)
    --18854-- REDIR: 0x3432e16220 (strcmp) redirected to 0x4a07e50 (strcmp)
    --18854-- REDIR: 0x3432e16330 (strlen) redirected to 0x4a07b50 (strlen)
    --18854-- Reading syms from /lib64/libc-2.8.so (0x3433200000)
    --18854-- REDIR: 0x3433281420 (rindex) redirected to 0x4a076f0 (rindex)
    --18854-- REDIR: 0x3433280f50 (strlen) redirected to 0x4a07b10 (strlen)
    --18854-- REDIR: 0x343327cd80 (malloc) redirected to 0x4a072d0 (malloc)
    --18854-- REDIR: 0x3433280a00 (strcpy) redirected to 0x4a07b70 (strcpy)
    ==18854== Invalid write of size 8
    ==18854==    at 0x4019D9: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==  Address 0x4c1a110 is 0 bytes after a block of size 16 alloc'd
    ==18854==    at 0x4A0739E: malloc (vg_replace_malloc.c:207)
    ==18854==    by 0x4018A4: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==
    ==18854== Invalid read of size 8
    ==18854==    at 0x4019F3: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==  Address 0x4c1a110 is 0 bytes after a block of size 16 alloc'd
    ==18854==    at 0x4A0739E: malloc (vg_replace_malloc.c:207)
    ==18854==    by 0x4018A4: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==
    ==18854== Invalid read of size 8
    ==18854==    at 0x401A20: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==  Address 0x4c1a110 is 0 bytes after a block of size 16 alloc'd
    ==18854==    at 0x4A0739E: malloc (vg_replace_malloc.c:207)
    ==18854==    by 0x4018A4: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==
    ==18854== Invalid read of size 8
    ==18854==    at 0x401A46: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==  Address 0x4c1a110 is 0 bytes after a block of size 16 alloc'd
    ==18854==    at 0x4A0739E: malloc (vg_replace_malloc.c:207)
    ==18854==    by 0x4018A4: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    --18854-- REDIR: 0x343327a7f0 (free) redirected to 0x4a05fd0 (free)
    --18854-- REDIR: 0xffffffffff600000 (???) redirected to 0x3802d093 (vgPlain_amd64_linux_REDIR_FOR_vgettimeofday)
    --18854-- REDIR: 0x34332848a0 (strchrnul) redirected to 0x4a088a0 (strchrnul)
    --18854-- REDIR: 0xffffffffff600400 (???) redirected to 0x3802d09d (vgPlain_amd64_linux_REDIR_FOR_vtime)
    --18854-- REDIR: 0x3433281040 (strnlen) redirected to 0x4a07ac0 (strnlen)
     ^13809^Idle:^art03.rar^glftpd^339913:10:15
    ==18854==
    ==18854== ERROR SUMMARY: 8 errors from 4 contexts (suppressed: 4 from 1)
    ==18854==
    ==18854== 2 errors in context 1 of 4:
    ==18854== Invalid read of size 8
    ==18854==    at 0x401A46: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==  Address 0x4c1a110 is 0 bytes after a block of size 16 alloc'd
    ==18854==    at 0x4A0739E: malloc (vg_replace_malloc.c:207)
    ==18854==    by 0x4018A4: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==
    ==18854== 2 errors in context 2 of 4:
    ==18854== Invalid read of size 8
    ==18854==    at 0x401A20: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==  Address 0x4c1a110 is 0 bytes after a block of size 16 alloc'd
    ==18854==    at 0x4A0739E: malloc (vg_replace_malloc.c:207)
    ==18854==    by 0x4018A4: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==
    ==18854== 2 errors in context 3 of 4:
    ==18854== Invalid read of size 8
    ==18854==    at 0x4019F3: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==  Address 0x4c1a110 is 0 bytes after a block of size 16 alloc'd
    ==18854==    at 0x4A0739E: malloc (vg_replace_malloc.c:207)
    ==18854==    by 0x4018A4: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==
    ==18854== 2 errors in context 4 of 4:
    ==18854== Invalid write of size 8
    ==18854==    at 0x4019D9: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    ==18854==  Address 0x4c1a110 is 0 bytes after a block of size 16 alloc'd
    ==18854==    at 0x4A0739E: malloc (vg_replace_malloc.c:207)
    ==18854==    by 0x4018A4: buffer_groups (in /root/tur-ftpwho)
    ==18854==    by 0x4014AD: main (in /root/tur-ftpwho)
    --18854--
    --18854-- supp:      4 dl-hack3-1
    ==18854==
    ==18854== IN SUMMARY: 8 errors from 4 contexts (suppressed: 4 from 1)
    ==18854==
    ==18854== malloc/free: in use at exit: 110 bytes in 9 blocks.
    ==18854== malloc/free: 11 allocs, 2 frees, 219 bytes allocated.
    ==18854==
    ==18854== searching for pointers to 9 not-freed blocks.
    ==18854== checked 64,272 bytes.
    ==18854==
    ==18854== LEAK SUMMARY:
    ==18854==    definitely lost: 47 bytes in 4 blocks.
    ==18854==      possibly lost: 0 bytes in 0 blocks.
    ==18854==    still reachable: 63 bytes in 5 blocks.
    ==18854==         suppressed: 0 bytes in 0 blocks.
    ==18854== Rerun with --leak-check=full to see details of leaked memory.
    --18854--  memcheck: sanity checks: 3 cheap, 2 expensive
    --18854--  memcheck: auxmaps: 58 auxmap entries (3712k, 3M) in use
    --18854--  memcheck: auxmaps_L1: 2006 searches, 10841 cmps, ratio 54:10
    --18854--  memcheck: auxmaps_L2: 75 searches, 58 nodes
    --18854--  memcheck: SMs: n_issued      = 15 (240k, 0M)
    --18854--  memcheck: SMs: n_deissued    = 0 (0k, 0M)
    --18854--  memcheck: SMs: max_noaccess  = 524287 (8388592k, 8191M)
    --18854--  memcheck: SMs: max_undefined = 0 (0k, 0M)
    --18854--  memcheck: SMs: max_defined   = 117 (1872k, 1M)
    --18854--  memcheck: SMs: max_non_DSM   = 15 (240k, 0M)
    --18854--  memcheck: max sec V bit nodes:    0 (0k, 0M)
    --18854--  memcheck: set_sec_vbits8 calls: 0 (new: 0, updates: 0)
    --18854--  memcheck: max shadow mem size:   4384k, 4M
    --18854-- translate:            fast SP updates identified: 1,186 ( 86.0%)
    --18854-- translate:   generic_known SP updates identified: 129 (  9.3%)
    --18854-- translate: generic_unknown SP updates identified: 64 (  4.6%)
    --18854--     tt/tc: 3,881 tt lookups requiring 3,942 probes
    --18854--     tt/tc: 3,881 fast-cache updates, 5 flushes
    --18854--  transtab: new        1,830 (42,362 -> 687,343; ratio 162:10) [0 scs]
    --18854--  transtab: dumped     0 (0 -> ??)
    --18854--  transtab: discarded  12 (257 -> ??)
    --18854-- scheduler: 362,540 jumps (bb entries).
    --18854-- scheduler: 3/2,124 major/minor sched events.
    --18854--    sanity: 4 cheap, 2 expensive checks.
    --18854--    exectx: 769 lists, 15 contexts (avg 0 per list)
    --18854--    exectx: 25 searches, 10 full compares (400 per 1000)
    --18854--    exectx: 0 cmp2, 28 cmp4, 0 cmpAll
    --18854--  errormgr: 8 supplist searches, 116 comparisons during search
    --18854--  errormgr: 12 errlist searches, 44 comparisons during search
    and finally the source:

    Code:
    #define VER     "3.0 (gl2.1)"
    #define KEY	0x0000DEAD   // Default KEY used by DAEMON
    #define GLGROUP "/mnt/array/glftpd/etc/group"
    
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <sys/time.h>
    #include <time.h>
    #include <errno.h>
    #include <ctype.h>
    #include <sys/types.h>
    #include <sys/ipc.h>
    #include <sys/shm.h>
    #include <syslog.h>
    #include <unistd.h>
    #include <sys/param.h>
    #include <fcntl.h>
    #include <sys/stat.h>
    
    struct ONLINE {
      char   tagline[64];             /* The users tagline */
      char   username[24];            /* The username of the user */
      char   status[256];             /* The status of the user, idle, RETR, etc */
      short int ssl_flag;             /* 0 = no ssl, 1 = ssl on control, 2 = ssl on control and data */
      char   host[256];               /* The host the user is comming from (with ident) */
      char   currentdir[256];         /* The users current dir (fullpath) */
      long   groupid;                 /* The groupid of the users primary group */
      time_t login_time;              /* The login time since the epoch (man 2 time) */
      struct timeval tstart;          /* replacement for last_update. */
      struct timeval txfer;           /* The time of the last succesfull transfer. */
      unsigned long long bytes_xfer;  /* bytes transferred so far. */
      unsigned long long bytes_txfer; /* bytes transferred in the last loop (speed limiting) */
      pid_t  procid;                  /* The processor id of the process */
    };
    
    static struct ONLINE *online;
    static int  dl = 0;
    static int  ul = 0;
    static int  num_users = 0;
    static int  shmid;
    static struct shmid_ds ipcbuf;
    
    static void quit();
    static double calc_time();
    
    struct GROUP {
    	char		*name;
    	gid_t		id;
    };
    
    int	groups = 0,
    	GROUPS = 0;
    
    static struct GROUP	**group;
    struct stat		 filestat;
    
    char* get_g_name(int gid) {
     int	n;
    
     for ( n = 0 ; n < groups ; n++ ) if ( group[n]->id == gid ) return group[n]->name;
     return "NoGroup";
    }
    
    static char *
    trim( char *str )
    {
      char *ibuf;
      char *obuf;
    
      if ( str )
        {
          for ( ibuf = obuf = str; *ibuf; )
            {
              while ( *ibuf && ( isspace ( *ibuf ) ) )
              ibuf++;
              if ( *ibuf && ( obuf != str ) )
                *( obuf++ ) = ' ';
              while ( *ibuf && ( !isspace ( *ibuf ) ) )
                *( obuf++ ) = *( ibuf++ );
            }
          *obuf = '\0';
        }
      return( str );
    }
    				 
    static char hmsbuf[50];			
    void
    pid_hms_format( time_t testtime )
    {
      time_t timenow = time( NULL );
      time_t difftime;
      int    days = 0;
      int    hours = 0;
      int    minutes = 0;
      int    seconds = 0;
    
      difftime = timenow - testtime;
       
      while ( difftime >= (time_t)3600 )
        {
          difftime -= (time_t)3600;
          hours++;
        }          
       
      while ( difftime >= (time_t)60 )
        {
          difftime -= (time_t)60;
          minutes++;
        }
       
      if ( hours != 0 )
        sprintf( hmsbuf, "%02d:%02d:%02d", hours, minutes, difftime );
      else
        sprintf( hmsbuf, "   %02d:%02d", minutes, difftime );
    }
    
    static int
    checkusers(void)
    {
      register int i, j, found = 0;
      char statbuf[ 500 ];
      char idletime[ 500 ];
      char pidbuf[ 10 ];
      char filename[20];
      char bar[20];
      struct timeval tstop;
      unsigned	hours;
      unsigned  char minutes;
      unsigned	seconds;
    	
      gettimeofday(&tstop, (struct timezone *)0);
    		
      for (i=0; i<num_users; i++) 
        {
          if (online[i].procid == 0)
            continue;
          sprintf( pidbuf, "%u", online[i].procid );
          pid_hms_format( online[i].tstart.tv_sec );  
    		
          if ((!strncasecmp (online[i].status, "STOR", 4) ||
    	  !strncasecmp (online[i].status, "APPE", 4)) &&
              online[i].bytes_xfer != 0) {
              strncpy(filename, online[i].status+5, sizeof(filename));
              j = strlen(filename);
              if (!isprint(filename[j-2]))
                filename[j-2] = '\0';
              else if (!isprint(filename[j-1]))
                filename[j-1] = '\0';
              sprintf( statbuf, "Up:^%.1f", calc_time(i) );
              sprintf( idletime, "", hmsbuf );
              ul++;
            }
          /* Downloading */
          else if (!strncasecmp (online[i].status, "RETR", 4) && online[i].bytes_xfer != 0)
            {
              strncpy(filename, online[i].status+5, sizeof(filename));
              j = strlen(filename);
              if (!isprint(filename[j-2]))
                filename[j-2] = '\0';
              else if (!isprint(filename[j-1]))
                filename[j-1] = '\0';
    
              sprintf( statbuf, "Dn:^%.1f", calc_time(i) );
              sprintf( idletime, "", hmsbuf );
              dl++;
            }
          /* Idling */
          else if (time(NULL) - online[i].tstart.tv_sec > 5)
            {
    	    *bar = *filename = hours = minutes = 0;
    	    seconds = tstop.tv_sec - online[i].tstart.tv_sec;
    	    while ( seconds >= 3600 ) { hours++;   seconds -= 3600; }
    	    while ( seconds >= 60 ) { minutes++; seconds -= 60; } 
    	    sprintf( statbuf, "Idle:", hmsbuf );
    	    sprintf( idletime, "%02d:%02d:%02d", hours, minutes, seconds);
            }
          /* Doing something else... */
          else
            {
              sprintf( statbuf, "\"%s\"", online[i].status );
              trim(statbuf);
              sprintf( idletime, "", hmsbuf );
            }
          pid_hms_format( online[i].login_time); 
          fprintf( stdout, "%-1.12s^%-1.5s^%-1.44s^%s^%s^%s\n", 
                  online[i].username, pidbuf, statbuf, online[i].currentdir, get_g_name(online[i].groupid), idletime);
          found++;
        }
      return (found);
    }
    
    int
    main( int argc, char **argv )
    {
      int numusers;
     
      if (argc >= 2)
      {
    
      if (strstr(argv[1],"-v") != NULL)
      { 
        printf ("Tur-FtpWho. A modified ftpwho by Turranius\n");
        printf ("Version %s - modified by f|lowman.\n",VER);
        quit (0);
      }  
    
      }
    
      buffer_groups(GLGROUP);
    
      if ((shmid = shmget( (key_t)KEY, 0, 0))
           == -1)
        {
          fprintf(stdout, "No Users Currently On Site!\n");
          exit(0);
        }
    
      if ((online = (struct ONLINE *)shmat( shmid, NULL, SHM_RDONLY))
          == (struct ONLINE *)-1)
        {
          fprintf(stdout, "Error: (SHMAT) Failed!\n");
          exit(1);
        }
    							     
      shmctl( shmid, IPC_STAT, &ipcbuf);
      num_users = ipcbuf.shm_segsz / sizeof( struct ONLINE );
    
      numusers = checkusers();
       
      quit( 0 );
    }
    
    static double
    calc_time(int pid)
    {
      struct timeval tstop;
      double delta, rate;
    
      if (online[pid].bytes_xfer < 1)
        return 0;
      gettimeofday(&tstop, (struct timezone *)0 );
      delta = ((tstop.tv_sec*10.)+(tstop.tv_usec/100000.)) -
             ((online[pid].tstart.tv_sec*10.)+(online[pid].tstart.tv_usec/100000.));
      delta = delta/10.;
      rate = ((online[pid].bytes_xfer / 1024.0) / (delta));
      if (!rate) rate++;
      return (double)(rate);
    }
    
    static void
    quit(int exit_status)
    {
      shmctl( shmid, IPC_STAT, &ipcbuf);
      if (ipcbuf.shm_nattch <= 1) {
        shmctl( shmid, IPC_RMID, 0);
      }
      shmdt(0);
      exit(exit_status);
    }
    
    /* Buffer groups file */
    int buffer_groups(char *groupfile) {
     char	*f_buf,
    	*g_name,
    	*f_name;
     long	f, n, m,
    	f_size,
    	g_id,
    	g_n_size,
    	l_start = 0;
    
     f_name = malloc( strlen(groupfile) + 2 );
     sprintf( f_name, "%s", groupfile );
    
     f = open( f_name, O_NONBLOCK );
     fstat( f, &filestat );
     f_size = filestat.st_size;
     f_buf  = malloc( f_size );
     read( f, f_buf, f_size );
    
     for ( n = 0 ; n < f_size ; n++ ) if ( f_buf[n] == '\n' ) GROUPS++;
     group = malloc( GROUPS * sizeof( int ) );
    
     for ( n = 0 ; n < f_size ; n++ ) {
      if ( f_buf[n] == '\n' || n == f_size ) {
       f_buf[n] = 0;
       m        = l_start;
       while ( f_buf[m] != ':' && m < n ) m++;
       if ( m != l_start ) {
        f_buf[m] = 0;
        g_name   = f_buf + l_start;
        g_n_size = m - l_start;
        m        = n;
        while ( f_buf[m] != ':' && m > l_start ) m--;
        f_buf[m] = 0;
        while ( f_buf[m] != ':' && m > l_start ) m--;
        if ( m != n ) {
         g_id = atoi( f_buf + m + 1 );
         group[groups] = malloc( sizeof( struct GROUP ) );
         group[groups]->name = malloc( g_n_size + 1 );
         strcpy( group[groups]->name, g_name );
         group[groups]->id = g_id;
         groups++;
        }
       }
       l_start = n + 1;
      }
     }
     
     close( f );
     free( f_buf );
     free( f_name );
    }
    Last edited by TehOne; 10-10-2008 at 07:21 PM.

  2. #2
    Registered User
    Join Date
    Oct 2001
    Posts
    2,129
    You don't free group or any element of group.

    edit: oh and it's generally considered a bad idea to be logged in as root all the time, especially for development stuff.

    edit: or any group[n]->name
    Last edited by robwhit; 10-10-2008 at 07:47 PM.

  3. #3
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    Quote Originally Posted by robwhit View Post
    You don't free group or any element of group.

    edit: oh and it's generally considered a bad idea to be logged in as root all the time, especially for development stuff.

    edit: or any group[n]->name
    Thanks for your answer, however my C knownlegend is unluckly no good plus it's not my application so more details would be highly appreciate or even better a direct example or fix would make me really happy!

    I am basically searching for a solution (fix) for the issue.
    Last edited by TehOne; 10-10-2008 at 07:56 PM.

  4. #4
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    Whenever you malloc or calloc something, you free it later. Just do that and it should be fixed.

    I don't know what your program does or how it does it, and I don't really feel like going through it ATM. If you want maintenance done on your programs, you could try hiring somebody on a site like rentacoder.com. These forums are generally meant for programmers trying to get some help on a specific problem. If you want to try to fix it yourself, here is some starter material:

    << !! Posting Code? Read this First !! >>
    Cprogramming.com: How to Get Started with C++
    Cprogramming.com - Programming Tutorials: C++ Made Easy and C Made Easy
    Cprogramming.com: FAQ
    C Book Recommendations
    C++ Book Recommendations - C Board
    C/C++ Reference
    cplusplus.com - The C++ Resources Network

  5. #5
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    I don't think I want to follow all the logic entirely... but I have seen a few things.

    Code:
    group = malloc( GROUPS * sizeof( int ) );
    should be
    Code:
    group = malloc( GROUPS * sizeof( struct GROUP * ) );
    but it may not make a difference if your machine int is same size as a pointer. It should be corrected never-the-less.

    Also, even though you are mallocating the number of elements as there are newlines '\n' in f_buf, your are traversing
    that array using some other complex counting criteria... which may exceed that limit. group[groups]... and then the index groups is incremented. Perhaps exceeding the limit of the array size. That's the part I didn't want to get into.

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