char far*ctxtAddress(const Context_Tag tag, const unsigned num)
{ char name[CTXT_ITEMNAME_LENGTH];
word ofs, segm;
ctxtMkItemName(name, tag, num);
segm = ctxtFromTag(tag);
assert(segm && segm != CTXT_INVALID);
if((ofs = env_findVar(segm, name)) != (word)-1)
return MK_FP(segm, ofs + strlen(name) + 1);
return 0;
}
int is_alias(const char * const name)
{ assert(name);
return env_findVar(ctxtAlias, name) != (unsigned)-1;
}
void aliasexpand(char * const cmd, const int maxlen)
{ char *hbuf; /* work buffer */
char *cp, *p;
unsigned ofs, *expanded, *he;
int i, numExpanded;
assert(cmd);
assert(strlen(cmd) < maxlen);
if((hbuf = malloc(maxlen)) == 0) {
error_out_of_memory();
return;
}
numExpanded = 0;
expanded = 0;
redo: /* iteration to expand all aliases */
cp = ltrimcl(cmd); /* skip leading whitespaces */
/* Check if the user disabled alias expansion */
if(*cp == '*') {
memmove(cmd, cp + 1, strlen(cp));
goto errRet;
}
/* Get the name of this command */
for(p = hbuf; is_fnchar(*cp) || *cp == '.';)
*p++ = *cp++;
if(p == hbuf || is_pathdelim(*cp) || is_quote(*cp))
/* no name || part of path -> no alias */
goto errRet;
*p = 0;
StrFUpr(hbuf); /* all aliases are uppercased */
if((ofs = env_findVar(ctxtAlias, hbuf)) == (unsigned)-1)
/* not found -> no alias */
goto errRet;
/* Prevent recursion by recording the offset of the found variable */
for(i = 0; i < numExpanded; ++i)
if(expanded[i] == ofs) /* already used -> ignore */
goto errRet;
if((he = realloc(expanded, ++numExpanded)) == 0) {
error_out_of_memory();
goto errRet;
}
expanded = he;
expanded[numExpanded - 1] = ofs;
/************ Expand the command line "cp" with the alias at
MK_FP(ctxtAlias, ofs) ***********************/
ofs += strlen(hbuf) + 1; /* advance to value */
if(_fstrlen(MK_FP(ctxtAlias, ofs)) < maxlen - strlen(cp)) {
/* prepend alias value to remaining command line */
_fstrcpy(TO_FP(hbuf), MK_FP(ctxtAlias, ofs));
strcat(hbuf, cp);
assert(strlen(hbuf) < maxlen);
strcpy(cmd, hbuf);
goto redo; /* next expansion */
}
error_command_too_long();
errRet: /* return to caller */
free(expanded);
free(hbuf);
}
int chgCtxt(const Context_Tag tag, const char * const name, const char * const value)
{ word segm, ofs;
int newlen;
assert(name);
ctxtCheckInfoTag(tag);
segm = ctxtFromTag(tag);
assert(segm);
newlen = value? strlen(name) + strlen(value) + 2: 0;
if((ofs = env_findVar(segm, name)) != (word)-1)
newlen -= env_varlen(segm, ofs);
/* Make sure the context has enough room to add the value to */
if(newlen > 0) { /* contents size will grow */
ctxt_info_t *hinfo, *dinfo;
/* aliases may not exceed sizemax */
if(tag == CTXT_TAG_ALIAS) {
if(CTXT_INFO(CTXT_TAG_ALIAS, sizemax)
- CTXT_INFO(CTXT_TAG_ALIAS, sizecur) < newlen) {
error_alias_out_of_memory();
return E_NoMem;
}
}
/* Otherwise a removeable entry is removed;
those are:
oldest item of history
oldest item of dirstack */
hinfo = segm == ctxtFromTag(CTXT_TAG_HISTORY)
? &CTXT_INFO_STRUCT(CTXT_TAG_HISTORY): 0;
dinfo = segm == ctxtFromTag(CTXT_TAG_DIRSTACK)
? &CTXT_INFO_STRUCT(CTXT_TAG_DIRSTACK): 0;
while(env_freeCount(segm) < newlen) {
/* There are two structures that can shrink:
history & dirstack */
if(hinfo && (hinfo->c_sizecur <= hinfo->c_sizemax
/* inconsitency of redundant info */
|| hinfo->c_nummin >= hinfo->c_nummax))
/* in range -> ignore */
hinfo = 0;
if(dinfo && (dinfo->c_sizecur <= dinfo->c_sizemax
/* inconsitency of redundant info */
|| dinfo->c_nummin >= dinfo->c_nummax))
/* in range -> ignore */
dinfo = 0;
if(hinfo && dinfo) { /* Choose one */
if(weight(hinfo) < weight(dinfo))
ctxtGet(1, CTXT_TAG_DIRSTACK, ++dinfo->c_nummin, 0);
else
ctxtGet(1, CTXT_TAG_HISTORY, ++hinfo->c_nummin, 0);
} else if(dinfo)
ctxtGet(1, CTXT_TAG_DIRSTACK, ++dinfo->c_nummin, 0);
else if(hinfo)
ctxtGet(1, CTXT_TAG_HISTORY, ++hinfo->c_nummin, 0);
else { /* no space left */
error_context_out_of_memory();
return E_NoMem;
}
}
}
/* return values 1 and 3 are OK */
switch(env_change(segm, name, value)) {
case 2: /* variable to delete not found <-> no problem */
case 1: case 3: /* var replaced | deleted | inserted ==> OK */
CTXT_INFO(tag, sizecur) += newlen;
return 0;
case 0: /* Cannot insert */
dprintf(("chgCtxt(): out-of-mem shouldn't occure here!\n"));
error_context_out_of_memory();
return E_NoMem;
default:
return E_Syntax;
}
}
char *aliasexpand(const char * const Xcmd)
{ char *cmd; /* work buffer */
char *cp, *name, *alias;
unsigned ofs, *expanded, *he;
int i, numExpanded, newlen, len;
assert(Xcmd);
if((cmd = estrdup(Xcmd)) == 0)
return (char*)Xcmd;
numExpanded = 0;
expanded = 0;
name = 0;
redo: /* iteration to expand all aliases */
cp = ltrimcl(cmd); /* skip leading whitespaces */
/* Check if the user disabled alias expansion */
if(*cp == '*') {
*cp = ' ';
goto errRet;
}
myfree(name);
/* Get the name of this command */
if((name = getCmdName(&(const char*)cp)) == 0 || is_pathdelim(*cp))
goto errRet;
StrFUpr(name); /* all aliases are uppercased */
if((ofs = env_findVar(ctxtAlias, name)) == (unsigned)-1)
/* not found -> no alias */
goto errRet;
/* Prevent recursion by recording the offset of the found variable */
for(i = 0; i < numExpanded; ++i)
if(expanded[i] == ofs) /* already used -> ignore */
goto errRet;
if((he = realloc(expanded, ++numExpanded)) == 0) {
error_out_of_memory();
goto errRet;
}
expanded = he;
expanded[numExpanded - 1] = ofs;
/************ Expand the command line "cp" with the alias at
MK_FP(ctxtAlias, ofs) ***********************/
alias = ctxtP(ctxtAlias, ofs + strlen(name) + 1);
/* Check that the total command line won't overflow MAX_INT */
if((newlen = strlen(alias)) >= 0
&& (len = strlen(cp)) >= 0 && ++len > 0 && newlen + len > 0) {
int dst = cp - cmd; /* destination index within cmd[] */
if(newlen > dst) {
/* need to increase the buffer */
char *p;
if((p = realloc(cmd, newlen + len)) == 0)
goto errRet1;
cmd = p;
}
/* else ignore to shrink the buffer; it will be done
automatically with the next ALIAS expansion or when
this function returns */
assert(len);
if(newlen != dst)
/* need to move the command tail */
memmove(&cmd[newlen], &cmd[dst], len);
/* prepend alias value to remaining command line */
memcpy(cmd, alias, newlen);
goto redo; /* next expansion */
}
errRet1:
error_long_internal_line();
errRet: /* return to caller */
myfree(expanded);
myfree(name);
return StrTrim(cmd);
}
