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Improve the IFS handling of the read built-in.

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Obtained from:	NetBSD
Submitted by:	Jilles Tjoelker
This commit is contained in:
stefanf 2009-03-22 22:09:12 +00:00
parent c0055de891
commit 7836b44d7b
1 changed files with 68 additions and 10 deletions
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78
bin/sh/miscbltin.c
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@ -73,6 +73,16 @@ int ulimitcmd(int, char **);
* ordinary characters. * ordinary characters.
* *
* This uses unbuffered input, which may be avoidable in some cases. * This uses unbuffered input, which may be avoidable in some cases.
*
* Note that if IFS=' :' then read x y should work so that:
* 'a b' x='a', y='b'
* ' a b ' x='a', y='b'
* ':b' x='', y='b'
* ':' x='', y=''
* '::' x='', y=''
* ': :' x='', y=''
* ':::' x='', y='::'
* ':b c:' x='', y='b c:'
*/ */
int int
@ -88,6 +98,8 @@ readcmd(int argc __unused, char **argv __unused)
int startword; int startword;
int status; int status;
int i; int i;
int is_ifs;
int saveall = 0;
struct timeval tv; struct timeval tv;
char *tvptr; char *tvptr;
fd_set ifds; fd_set ifds;
@ -167,7 +179,7 @@ readcmd(int argc __unused, char **argv __unused)
} }
status = 0; status = 0;
startword = 1; startword = 2;
backslash = 0; backslash = 0;
STARTSTACKSTR(p); STARTSTACKSTR(p);
for (;;) { for (;;) {
@ -189,22 +201,68 @@ readcmd(int argc __unused, char **argv __unused)
} }
if (c == '\n') if (c == '\n')
break; break;
if (startword && *ifs == ' ' && strchr(ifs, c)) { if (strchr(ifs, c))
is_ifs = strchr(" \t\n", c) ? 1 : 2;
else
is_ifs = 0;
if (startword != 0) {
if (is_ifs == 1) {
/* Ignore leading IFS whitespace */
if (saveall)
STPUTC(c, p);
continue;
}
if (is_ifs == 2 && startword == 1) {
/* Only one non-whitespace IFS per word */
startword = 2;
if (saveall)
STPUTC(c, p);
continue;
}
}
if (is_ifs == 0) {
/* append this character to the current variable */
startword = 0;
if (saveall)
/* Not just a spare terminator */
saveall++;
STPUTC(c, p);
continue; continue;
} }
startword = 0;
if (ap[1] != NULL && strchr(ifs, c) != NULL) { /* end of variable... */
STACKSTRNUL(p); startword = is_ifs;
setvar(*ap, stackblock(), 0);
ap++; if (ap[1] == NULL) {
startword = 1; /* Last variable needs all IFS chars */
STARTSTACKSTR(p); saveall++;
} else {
STPUTC(c, p); STPUTC(c, p);
continue;
} }
STACKSTRNUL(p);
setvar(*ap, stackblock(), 0);
ap++;
STARTSTACKSTR(p);
} }
STACKSTRNUL(p); STACKSTRNUL(p);
/* Remove trailing IFS chars */
for (; stackblock() <= --p; *p = 0) {
if (!strchr(ifs, *p))
break;
if (strchr(" \t\n", *p))
/* Always remove whitespace */
continue;
if (saveall > 1)
/* Don't remove non-whitespace unless it was naked */
break;
}
setvar(*ap, stackblock(), 0); setvar(*ap, stackblock(), 0);
/* Set any remaining args to "" */
while (*++ap != NULL) while (*++ap != NULL)
setvar(*ap, nullstr, 0); setvar(*ap, nullstr, 0);
return status; return status;