--- /dev/null
+.\" $NetBSD: fparseln.3,v 1.4 2009/10/21 01:07:45 snj Exp $
+.\"
+.\" Copyright (c) 1997 Christos Zoulas. All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\" notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.\"
+.Dd November 30, 2002
+.Dt FPARSELN 3
+.Os
+.Sh NAME
+.Nm fparseln
+.Nd return the next logical line from a stream
+.Sh LIBRARY
+.ds str-Lb-libbsd Utility functions from BSD systems (libbsd, \-lbsd)
+.Lb libbsd
+.Sh SYNOPSIS
+.In bsd/stdio.h
+.Ft "char *"
+.Fo "fparseln"
+.Fa "FILE *stream" "size_t *len" "size_t *lineno"
+.Fa "const char delim[3]" "int flags"
+.Fc
+.Sh DESCRIPTION
+The
+.Fn fparseln
+function
+returns a pointer to the next logical line from the stream referenced by
+.Fa stream .
+This string is
+.Dv NUL
+terminated and it is dynamically allocated on each invocation.
+It is the responsibility of the caller to free the pointer.
+.Pp
+By default, if a character is escaped, both it and the preceding escape
+character will be present in the returned string.
+Various
+.Fa flags
+alter this behaviour.
+.Pp
+The meaning of the arguments is as follows:
+.Bl -tag -width "lineno"
+.It Fa stream
+The stream to read from.
+.It Fa len
+If not
+.Dv NULL ,
+the length of the string is stored in the memory location to which it
+points.
+.It Fa lineno
+If not
+.Dv NULL ,
+the value of the memory location to which is pointed to, is incremented
+by the number of lines actually read from the file.
+.It Fa delim
+Contains the escape, continuation, and comment characters.
+If a character is
+.Dv NUL
+then processing for that character is disabled.
+If
+.Dv NULL ,
+all characters default to values specified below.
+The contents of
+.Fa delim
+is as follows:
+.Bl -tag -width "delim[0]"
+.It Fa delim[0]
+The escape character, which defaults to
+.Cm \e ,
+is used to remove any special meaning from the next character.
+.It Fa delim[1]
+The continuation character, which defaults to
+.Cm \e ,
+is used to indicate that the next line should be concatenated with the
+current one if this character is the last character on the current line
+and is not escaped.
+.It Fa delim[2]
+The comment character, which defaults to
+.Cm # ,
+if not escaped indicates the beginning of a comment that extends until the
+end of the current line.
+.El
+.It Fa flags
+If non-zero, alter the operation of
+.Fn fparseln .
+The various flags, which may be
+.Em or Ns -ed
+together, are:
+.Bl -tag -width "FPARSELN_UNESCCOMM"
+.It Dv FPARSELN_UNESCCOMM
+Remove escape preceding an escaped comment.
+.It Dv FPARSELN_UNESCCONT
+Remove escape preceding an escaped continuation.
+.It Dv FPARSELN_UNESCESC
+Remove escape preceding an escaped escape.
+.It Dv FPARSELN_UNESCREST
+Remove escape preceding any other character.
+.It Dv FPARSELN_UNESCALL
+All of the above.
+.El
+.Pp
+.El
+.Sh RETURN VALUES
+Upon successful completion a pointer to the parsed line is returned;
+otherwise,
+.Dv NULL
+is returned.
+.Pp
+The
+.Fn fparseln
+function uses internally
+.Xr fgetln 3 ,
+so all error conditions that apply to
+.Xr fgetln 3 ,
+apply to
+.Fn fparseln .
+In addition
+.Fn fparseln
+may set
+.Va errno
+to
+.Bq Er ENOMEM
+and return
+.Dv NULL
+if it runs out of memory.
+.Sh SEE ALSO
+.Xr fgetln 3
+.Sh HISTORY
+The
+.Fn fparseln
+function first appeared in
+.Nx 1.4 .
--- /dev/null
+/* $NetBSD: fparseln.c,v 1.10 2009/10/21 01:07:45 snj Exp $ */
+
+/*
+ * Copyright (c) 1997 Christos Zoulas. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+__RCSID("$NetBSD: fparseln.c,v 1.10 2009/10/21 01:07:45 snj Exp $");
+#endif /* LIBC_SCCS and not lint */
+
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#define FLOCKFILE(fp)
+#define FUNLOCKFILE(fp)
+#define _DIAGASSERT(t)
+
+static int isescaped(const char *, const char *, int);
+
+/* isescaped():
+ * Return true if the character in *p that belongs to a string
+ * that starts in *sp, is escaped by the escape character esc.
+ */
+static int
+isescaped(const char *sp, const char *p, int esc)
+{
+ const char *cp;
+ size_t ne;
+
+ _DIAGASSERT(sp != NULL);
+ _DIAGASSERT(p != NULL);
+
+ /* No escape character */
+ if (esc == '\0')
+ return 0;
+
+ /* Count the number of escape characters that precede ours */
+ for (ne = 0, cp = p; --cp >= sp && *cp == esc; ne++)
+ continue;
+
+ /* Return true if odd number of escape characters */
+ return (ne & 1) != 0;
+}
+
+
+/* fparseln():
+ * Read a line from a file parsing continuations ending in \
+ * and eliminating trailing newlines, or comments starting with
+ * the comment char.
+ */
+char *
+fparseln(FILE *fp, size_t *size, size_t *lineno, const char str[3], int flags)
+{
+ static const char dstr[3] = { '\\', '\\', '#' };
+
+ size_t s, len;
+ char *buf;
+ char *ptr, *cp;
+ int cnt;
+ char esc, con, nl, com;
+
+ _DIAGASSERT(fp != NULL);
+
+ len = 0;
+ buf = NULL;
+ cnt = 1;
+
+ if (str == NULL)
+ str = dstr;
+
+ esc = str[0];
+ con = str[1];
+ com = str[2];
+ /*
+ * XXX: it would be cool to be able to specify the newline character,
+ * but unfortunately, fgetln does not let us
+ */
+ nl = '\n';
+
+ FLOCKFILE(fp);
+
+ while (cnt) {
+ cnt = 0;
+
+ if (lineno)
+ (*lineno)++;
+
+ if ((ptr = fgetln(fp, &s)) == NULL)
+ break;
+
+ if (s && com) { /* Check and eliminate comments */
+ for (cp = ptr; cp < ptr + s; cp++)
+ if (*cp == com && !isescaped(ptr, cp, esc)) {
+ s = cp - ptr;
+ cnt = s == 0 && buf == NULL;
+ break;
+ }
+ }
+
+ if (s && nl) { /* Check and eliminate newlines */
+ cp = &ptr[s - 1];
+
+ if (*cp == nl)
+ s--; /* forget newline */
+ }
+
+ if (s && con) { /* Check and eliminate continuations */
+ cp = &ptr[s - 1];
+
+ if (*cp == con && !isescaped(ptr, cp, esc)) {
+ s--; /* forget continuation char */
+ cnt = 1;
+ }
+ }
+
+ if (s == 0) {
+ /*
+ * nothing to add, skip realloc except in case
+ * we need a minimal buf to return an empty line
+ */
+ if (cnt || buf != NULL)
+ continue;
+ }
+
+ if ((cp = realloc(buf, len + s + 1)) == NULL) {
+ FUNLOCKFILE(fp);
+ free(buf);
+ return NULL;
+ }
+ buf = cp;
+
+ (void) memcpy(buf + len, ptr, s);
+ len += s;
+ buf[len] = '\0';
+ }
+
+ FUNLOCKFILE(fp);
+
+ if ((flags & FPARSELN_UNESCALL) != 0 && esc && buf != NULL &&
+ strchr(buf, esc) != NULL) {
+ ptr = cp = buf;
+ while (cp[0] != '\0') {
+ int skipesc;
+
+ while (cp[0] != '\0' && cp[0] != esc)
+ *ptr++ = *cp++;
+ if (cp[0] == '\0' || cp[1] == '\0')
+ break;
+
+ skipesc = 0;
+ if (cp[1] == com)
+ skipesc += (flags & FPARSELN_UNESCCOMM);
+ if (cp[1] == con)
+ skipesc += (flags & FPARSELN_UNESCCONT);
+ if (cp[1] == esc)
+ skipesc += (flags & FPARSELN_UNESCESC);
+ if (cp[1] != com && cp[1] != con && cp[1] != esc)
+ skipesc = (flags & FPARSELN_UNESCREST);
+
+ if (skipesc)
+ cp++;
+ else
+ *ptr++ = *cp++;
+ *ptr++ = *cp++;
+ }
+ *ptr = '\0';
+ len = strlen(buf);
+ }
+
+ if (size)
+ *size = len;
+ return buf;
+}
+
+#ifdef TEST
+
+int main(int, char **);
+
+int
+main(int argc, char **argv)
+{
+ char *ptr;
+ size_t size, line;
+
+ line = 0;
+ while ((ptr = fparseln(stdin, &size, &line, NULL,
+ FPARSELN_UNESCALL)) != NULL)
+ printf("line %d (%d) |%s|\n", line, size, ptr);
+ return 0;
+}
+
+/*
+
+# This is a test
+line 1
+line 2 \
+line 3 # Comment
+line 4 \# Not comment \\\\
+
+# And a comment \
+line 5 \\\
+line 6
+
+*/
+
+#endif /* TEST */
projects / thirdparty / libbsd.git / commitdiff
