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author | Arnold D. Robbins <arnold@skeeve.com> | 2010-07-16 14:52:31 +0300 |
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committer | Arnold D. Robbins <arnold@skeeve.com> | 2010-07-16 14:52:31 +0300 |
commit | 3ba50a15ebd976f7a88393e2e45dc14b6478b9a9 (patch) | |
tree | 6a6bbe6bed1141051fefe94b2d39eacd4854235a /libsigsegv/src/stackvma-rofile.c | |
parent | 6a2caf2157d87b4b582b2494bdd7d6a688dd0b1f (diff) | |
download | egawk-3ba50a15ebd976f7a88393e2e45dc14b6478b9a9.tar.gz egawk-3ba50a15ebd976f7a88393e2e45dc14b6478b9a9.tar.bz2 egawk-3ba50a15ebd976f7a88393e2e45dc14b6478b9a9.zip |
Move to gawk-3.1.7.
Diffstat (limited to 'libsigsegv/src/stackvma-rofile.c')
-rw-r--r-- | libsigsegv/src/stackvma-rofile.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/libsigsegv/src/stackvma-rofile.c b/libsigsegv/src/stackvma-rofile.c new file mode 100644 index 00000000..d6d19394 --- /dev/null +++ b/libsigsegv/src/stackvma-rofile.c @@ -0,0 +1,121 @@ +/* Buffered read-only streams. + Copyright (C) 2008 Bruno Haible <bruno@clisp.org> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +#include <errno.h> /* errno, EINTR */ +#include <fcntl.h> /* O_RDONLY */ +#include <stddef.h> /* size_t */ +#include <unistd.h> /* read, close */ + +/* Buffered read-only streams. + We cannot use <stdio.h> here, because fopen() calls malloc(), and a malloc() + call may have been interrupted. */ + +struct rofile + { + int fd; + size_t position; + size_t filled; + int eof_seen; + char buffer[4096]; + }; + +/* Open a read-only file stream. */ +static int +rof_open (struct rofile *rof, const char *filename) +{ + int fd = open (filename, O_RDONLY); + if (fd < 0) + return -1; + rof->fd = fd; + rof->position = 0; + rof->filled = 0; + rof->eof_seen = 0; + return 0; +} + +/* Return the next byte from a read-only file stream without consuming it, + or -1 at EOF. */ +static int +rof_peekchar (struct rofile *rof) +{ + if (rof->position == rof->filled) + { + if (rof->eof_seen) + return -1; + else + for (;;) + { + int n = read (rof->fd, rof->buffer, sizeof (rof->buffer)); +#ifdef EINTR + if (n < 0 && errno == EINTR) + continue; +#endif + if (n <= 0) + { + rof->eof_seen = 1; + return -1; + } + rof->filled = n; + rof->position = 0; + break; + } + } + return (unsigned char) rof->buffer[rof->position]; +} + +/* Return the next byte from a read-only file stream, or -1 at EOF. */ +static int +rof_getchar (struct rofile *rof) +{ + int c = rof_peekchar (rof); + if (c >= 0) + rof->position++; + return c; +} + +/* Parse an unsigned hexadecimal number from a read-only file stream. */ +static int +rof_scanf_lx (struct rofile *rof, unsigned long *valuep) +{ + unsigned long value = 0; + unsigned int numdigits = 0; + for (;;) + { + int c = rof_peekchar (rof); + if (c >= '0' && c <= '9') + value = (value << 4) + (c - '0'); + else if (c >= 'A' && c <= 'F') + value = (value << 4) + (c - 'A' + 10); + else if (c >= 'a' && c <= 'f') + value = (value << 4) + (c - 'a' + 10); + else + break; + rof_getchar (rof); + numdigits++; + } + if (numdigits == 0) + return -1; + *valuep = value; + return 0; +} + +/* Close a read-only file stream. */ +static void +rof_close (struct rofile *rof) +{ + close (rof->fd); +} |