mdw@git.distorted.org.uk Git - fastforward/blob - setforward.c

   1 #include "substdio.h"
   2 #include "subfd.h"
   3 #include "strerr.h"
   4 #include "stralloc.h"
   5 #include "open.h"
   6 #include "case.h"
   7 #include "readwrite.h"
   8 #include "cdbmss.h"
   9
  10 #define FATAL "setforward: fatal: "
  11
  12 void usage()
  13 {
  14   strerr_die1x(100,"setforward: usage: setforward data.cdb data.tmp");
  15 }
  16 void nomem()
  17 {
  18   strerr_die2x(111,FATAL,"out of memory");
  19 }
  20 void missingsemicolon()
  21 {
  22   strerr_die2x(100,FATAL,"final instruction must end with semicolon");
  23 }
  24 void extracolon()
  25 {
  26   strerr_die2x(100,FATAL,"double colons are not permitted");
  27 }
  28 void extracomma()
  29 {
  30   strerr_die2x(100,FATAL,"commas are not permitted before colons");
  31 }
  32 void nulbyte()
  33 {
  34   strerr_die2x(100,FATAL,"NUL bytes are not permitted");
  35 }
  36 void longaddress()
  37 {
  38   strerr_die2x(100,FATAL,"addresses over 800 bytes are not permitted");
  39 }
  40
  41 char *fncdb;
  42 char *fntmp;
  43 int fd;
  44 struct cdbmss cdbmss;
  45 stralloc key = {0};
  46
  47 stralloc target = {0}; /* always initialized; no NUL */
  48 stralloc command = {0}; /* always initialized; no NUL */
  49 stralloc instr = {0}; /* always initialized */
  50
  51 int flagtarget = 0;
  52 /* 0: reading target; command is empty; instr is empty */
  53 /* 1: target is complete; instr still has to be written; reading command */
  54
  55 void writeerr()
  56 {
  57   strerr_die4sys(111,FATAL,"unable to write to ",fntmp,": ");
  58 }
  59
  60 void doit(prepend,data,datalen)
  61 char *prepend;
  62 char *data;
  63 int datalen;
  64 {
  65   if (!stralloc_copys(&key,prepend)) nomem();
  66   if (!stralloc_cat(&key,&target)) nomem();
  67   case_lowerb(key.s,key.len);
  68   if (cdbmss_add(&cdbmss,key.s,key.len,data,datalen) == -1)
  69     writeerr();
  70 }
  71
  72 int getch(ch)
  73 char *ch;
  74 {
  75   int r;
  76
  77   r = substdio_get(subfdinsmall,ch,1);
  78   if (r == -1)
  79     strerr_die2sys(111,FATAL,"unable to read input: ");
  80   return r;
  81 }
  82
  83 void main(argc,argv)
  84 int argc;
  85 char **argv;
  86 {
  87   char ch;
  88   int r;
  89
  90   if (!stralloc_copys(&target,"")) nomem();
  91   if (!stralloc_copys(&command,"")) nomem();
  92   if (!stralloc_copys(&instr,"")) nomem();
  93
  94   fncdb = argv[1]; if (!fncdb) usage();
  95   fntmp = argv[2]; if (!fntmp) usage();
  96
  97   fd = open_trunc(fntmp);
  98   if (fd == -1)
  99     strerr_die4sys(111,FATAL,"unable to create ",fntmp,": ");
 100
 101   if (cdbmss_start(&cdbmss,fd) == -1) writeerr();
 102
 103   for (;;) {
 104     if (!getch(&ch)) goto eof;
 105
 106     if (ch == '#') {
 107       while (ch != '\n') if (!getch(&ch)) goto eof;
 108       continue;
 109     }
 110
 111     if (ch == ' ') continue;
 112     if (ch == '\n') continue;
 113     if (ch == '\t') continue;
 114
 115     if (ch == ':') {
 116       if (flagtarget) extracolon();
 117       flagtarget = 1;
 118       continue;
 119     }
 120
 121     if ((ch == ',') || (ch == ';')) {
 122       if (!flagtarget) extracomma();
 123       if (command.len) {
 124         if (command.s[0] == '?') {
 125           doit("?",command.s + 1,command.len - 1);
 126         }
 127         else if ((command.s[0] == '|') || (command.s[0] == '!')) {
 128           if (!stralloc_cat(&instr,&command)) nomem();
 129           if (!stralloc_0(&instr)) nomem();
 130         }
 131         else if ((command.s[0] == '.') || (command.s[0] == '/')) {
 132           if (!stralloc_cat(&instr,&command)) nomem();
 133           if (!stralloc_0(&instr)) nomem();
 134         }
 135         else {
 136           if (command.len > 800) longaddress();
 137           if (command.s[0] != '&')
 138             if (!stralloc_cats(&instr,"&")) nomem();
 139           if (!stralloc_cat(&instr,&command)) nomem();
 140           if (!stralloc_0(&instr)) nomem();
 141         }
 142       }
 143
 144       if (!stralloc_copys(&command,"")) nomem();
 145
 146       if (ch == ';') {
 147         if (instr.len)
 148           doit(":",instr.s,instr.len);
 149
 150         if (!stralloc_copys(&target,"")) nomem();
 151         if (!stralloc_copys(&instr,"")) nomem();
 152         flagtarget = 0;
 153       }
 154       continue;
 155     }
 156
 157     if (ch == '\\') if (!getch(&ch)) goto eof;
 158     if (ch == 0) nulbyte();
 159     if (!stralloc_append(flagtarget ? &command : &target,&ch)) nomem();
 160   }
 161
 162   eof:
 163   if (flagtarget || target.len)
 164     missingsemicolon();
 165
 166   if (cdbmss_finish(&cdbmss) == -1) writeerr();
 167   if (fsync(fd) == -1) writeerr();
 168   if (close(fd) == -1) writeerr(); /* NFS stupidity */
 169
 170   if (rename(fntmp,fncdb) == -1)
 171     strerr_die6sys(111,FATAL,"unable to move ",fntmp," to ",fncdb,": ");
 172
 173   _exit(0);
 174 }