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Split rdline into multiple, easier to read functions

Signed-off-by: David Oberhollenzer <david.oberhollenzer@tele2.at>
This commit is contained in:
David Oberhollenzer 2018-04-04 23:37:20 +02:00
parent 65d2abc3f0
commit 00daf470d1

View file

@ -17,130 +17,153 @@
*/
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include "util.h"
enum {
STATE_INITIAL = 0,
STATE_STRING = 1,
STATE_STRING_ESC = 2,
STATE_COMMENT = 3,
STATE_ARG = 4,
};
typedef struct {
int fd; /* input file descriptor */
const char *argstr; /* if not NULL, read from this instead */
size_t i; /* buffer offset */
size_t bufsiz; /* buffer size */
char *buffer;
bool string; /* inside a string? */
bool escape; /* reading an escape sequence? */
bool comment; /* inside a comment */
} rdline_t;
static int rdline_getc(rdline_t *t)
{
int ret;
char c;
if (t->argstr != NULL) {
c = *(t->argstr++);
if (c != '\0')
goto out;
t->argstr = NULL;
}
do {
ret = read(t->fd, &c, 1);
} while (ret < 0 && errno == EINTR);
if (ret < 0)
return -1;
if (ret == 0) {
if (t->i == 0) {
errno = 0;
return -1;
}
c = '\0';
}
out:
return (c == '\n') ? '\0' : c;
}
static int rdline_append(rdline_t *t, int c)
{
size_t newsz;
char *new;
if (t->comment) {
if (c != '\0')
return 0;
} else if (t->string) {
if (t->escape) {
t->escape = false;
} else {
if (c == '\\')
t->escape = true;
if (c == '"')
t->string = false;
}
} else {
if (isspace(c))
c = ' ';
if (c == ' ' && (t->i == 0 || t->buffer[t->i - 1] == ' '))
return 0;
if (c == '#') {
t->comment = true;
return 0;
}
if (c == '"')
t->string = true;
}
if (c == '\0') {
while (t->i > 0 && t->buffer[t->i - 1] == ' ')
t->i -= 1;
}
if (t->i == t->bufsiz) {
newsz = t->bufsiz ? t->bufsiz * 2 : 16;
new = realloc(t->buffer, newsz);
if (new == NULL)
return -1;
t->buffer = new;
t->bufsiz = newsz;
}
t->buffer[t->i++] = c;
return 0;
}
char *rdline(int fd, int argc, const char *const *argv)
{
size_t i = 0, bufsiz = 0, newsz;
int ret, state = STATE_INITIAL;
char c, *new, *buffer = NULL;
const char *argstr = NULL;
rdline_t rd;
int ret;
char c;
for (;;) {
if (argstr == NULL) {
switch (read(fd, &c, 1)) {
case 0:
if (i == 0) {
errno = 0;
return NULL;
memset(&rd, 0, sizeof(rd));
rd.fd = fd;
do {
c = rdline_getc(&rd);
if (c < 0)
goto fail;
if (c == 0 && rd.string) {
errno = EILSEQ;
goto fail;
}
if (c == '%') {
c = rdline_getc(&rd);
if (c == 0)
errno = EILSEQ;
if (c <= 0)
goto fail;
if (c != '%') {
if (!isdigit(c) || (c - '0') >= argc) {
errno = EINVAL;
goto fail;
}
c = '\0';
break;
case 1:
break;
default:
if (errno == EINTR)
continue;
goto fail;
}
} else {
c = *(argstr++);
if (c == '\0') {
argstr = NULL;
if (rd.argstr != NULL) {
errno = ELOOP;
goto fail;
}
rd.argstr = argv[c - '0'];
continue;
}
}
if (c == '\n')
c = '\0';
if (rdline_append(&rd, c))
goto fail;
} while (c != '\0');
switch (state) {
case STATE_STRING:
if (c == '\\')
state = STATE_STRING_ESC;
if (c == '"')
state = STATE_INITIAL;
break;
case STATE_STRING_ESC:
state = STATE_STRING;
break;
case STATE_COMMENT:
if (c != '\0')
continue;
break;
case STATE_ARG:
state = STATE_INITIAL;
if (c == '%')
break;
if (!isdigit(c) || (c - '0') >= argc) {
errno = EINVAL;
goto fail;
}
if (argstr != NULL) {
errno = ELOOP;
goto fail;
}
argstr = argv[c - '0'];
continue;
default:
if (isspace(c))
c = ' ';
if (c == ' ' && (i == 0 || buffer[i - 1] == ' '))
continue;
if (c == '#') {
state = STATE_COMMENT;
continue;
}
if (c == '%') {
state = STATE_ARG;
continue;
}
if (c == '"')
state = STATE_STRING;
break;
}
if (c == '\0') {
while (i > 0 && buffer[i - 1] == ' ')
--i;
}
if (i == bufsiz) {
newsz = bufsiz ? bufsiz * 2 : 16;
new = realloc(buffer, newsz);
if (new == NULL)
goto fail;
buffer = new;
bufsiz = newsz;
}
buffer[i++] = c;
if (c == '\0')
break;
}
if (state == STATE_STRING || state == STATE_STRING_ESC) {
errno = EILSEQ;
goto fail;
}
return buffer;
return rd.buffer;
fail:
ret = errno;
free(buffer);
free(rd.buffer);
errno = ret;
return NULL;
}