void aliasexpand(char *cmd, int maxlen)
{
char *cp;
unsigned m;
unsigned len;
short expanded;
TAlias *ptr;
assert(cmd);
if (++useFlag == 0) /* (int) overflow */
{ /* The useFlag specifies, if the particular
ALIAS is used by the _current_ expand.
To avoid to clear the flag each time when
to expand a string a different flag value
is used each time. */
if((ptr = first) != NULL)
/* reset all values to be sure we hit no old one */
do ptr->used = 0;
while((ptr = ptr->next) != NULL);
useFlag = 1;
}
cp = ltrim(cmd); /* skip leading whitespaces */
/* Check if the user disabled alias expansion */
if (*cp == '*')
{
cp = ltrim(cp + 1);
memmove(cmd, cp, strlen(cp) + 1);
return;
}
/* this allows to case-sensitively compare strings, which
is much faster */
partstrlower(cp);
/* to simplify the loop below */
memmove(cmd, cp, strlen(cp) + 1);
/* substitution loop */
/* Empty alias list --> no loop */
if(first) do {
expanded = 0;
ptr = first;
do {
assert(ptr);
assert(ptr->name);
assert(ptr->subst);
len = strlen(ptr->name);
if ((isspace(cmd[len]) || cmd[len] == '\0') /* end of word */
&& !strncmp(cmd, ptr->name, len) /* line begins with alias */
&& ptr->used != useFlag) /* this alias unused */
{
m = strlen(ptr->subst);
if (strlen(cmd) - len + m > maxlen)
{
error_command_too_long();
cmd[0] = '\0'; /* the parser won't cause any problems
with an empty line */
return;
}
else
{
/* adjust the remaining part within the command line */
memmove(&cmd[m], &cmd[len], strlen(&cmd[len]) + 1);
/* prepend the alias substitution */
memcpy(&cmd[0], &ptr->subst[0], m);
ptr->used = useFlag;
expanded = 1;
}
}
} while((ptr = ptr->next) != NULL);
} while(expanded);
}
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);
}
