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[elftoolchain-vcs-changes] SF.net SVN: elftoolchain: [3] projects/strings/trunk
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From: <jk...@us...> - 2008-04-02 09:44:30
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Revision: 3
http://elftoolchain.svn.sourceforge.net/elftoolchain/?rev=3&view=rev
Author: jkoshy
Date: 2008-04-02 02:44:26 -0700 (Wed, 02 Apr 2008)
Log Message:
-----------
Add an implementation of strings(1) contributed by Sam Arun Raj.
Added Paths:
-----------
projects/strings/trunk/Makefile
projects/strings/trunk/strings.1
projects/strings/trunk/strings.c
Added: projects/strings/trunk/Makefile
===================================================================
--- projects/strings/trunk/Makefile (rev 0)
+++ projects/strings/trunk/Makefile 2008-04-02 09:44:26 UTC (rev 3)
@@ -0,0 +1,8 @@
+#
+
+PROG= strings
+WARNS?= 6
+LDADD= -lelf
+
+.include <bsd.prog.mk>
+
Added: projects/strings/trunk/strings.1
===================================================================
--- projects/strings/trunk/strings.1 (rev 0)
+++ projects/strings/trunk/strings.1 2008-04-02 09:44:26 UTC (rev 3)
@@ -0,0 +1,141 @@
+.\" Copyright (c) 2007 S.Sam Arun Raj
+.\" 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd April 15, 2007
+.Dt STRINGS 1
+.Os
+.Sh NAME
+.Nm strings
+.Nd "print the strings of printable characters in files"
+.Sh SYNOPSIS
+.Nm
+.Op Fl afho
+.Op Fl e Ar encoding
+.Op Fl n Ar number
+.Op Fl t Ar radix
+.Op Ar
+.Sh DESCRIPTION
+Fo each
+.Ar file
+given, the
+.Nm
+utility prints any contiguous seqeunce of printable
+characters of atleast 'n' characters long (the default is 4 characters)
+followed by an unprintable character.
+.Nm
+only scans the initialized and loaded sections of ELF objects; for other
+file types, the entire file is scanned.
+The
+.Nm
+utility is mainly useful for determining the contents of non-text files.
+.Pp
+If no file name is specified in the input, standard input is read from.
+.Pp
+The following options are available:
+.Bl -tag -width indent
+.It Fl a
+This option instructs
+.Nm
+to scan the entire file. This is useful to override the default behaviour of
+scanning only initialized and loaded section of ELF objects.
+.It Fl e Ar encoding
+Select the character encoding to be used while searching for strings.
+The encoding depends on the single character argument which speicifes
+the encoding;
+.Ar s
+for single 7-bit-byte characters (ASCII, ISO 8859, etc., default).
+.Ar S
+for single 8-bit-byte characters.
+.Ar l
+for 16-bit littleendian.
+.Ar b
+for 16-bit bigendian.
+.Ar L
+for 32-bit littleendian.
+.Ar B
+for 32-bit bigendian.
+.It Fl f
+Print the name of the file before each string.
+.It Fl t Ar radix
+Print the offset from the start of the file before each string. The
+format depends on the single character argument which specifies the
+radix of the offset;
+.Ar d
+for decimal,
+.Ar o
+for octal,
+.Ar x
+for hexadecimal.
+.It Fl n Ar number
+Print the contiguous character sequence of alteast
+.Ar number
+characters long, instead of default 4 characters.
+.It Fl o
+This is same as -t o.
+.It Fl h
+This prints a usage summary and exits.
+.El
+.Sh EXIT STATUS
+.Ex -std
+.Sh EXAMPLES
+The following are examples of typical usage
+of the
+.Nm
+command:
+.Dl ""
+.Dl "$ strings /bin/ls"
+.Dl "$ strings -a /bin/ln"
+.Dl "$ strings -a -f -t x /bin/cat"
+.Sh SEE ALSO
+.Xr ar 1 ,
+.Xr nm 1 ,
+.Xr objdump 1 ,
+.Xr ranlib ,
+.Xr readelf 1
+.Sh HISTORY
+The first FreeBSD
+.Nm
+utility appeared in
+.Fx v3.
+It was later discontinued in
+.Fx v5 ,
+when i386-only a.out format was dropped in favor of ELF.
+.Sh AUTHORS
+.An -nosplit
+The
+.Nm
+utility was re-written by
+.An S.Sam Arun Raj Aq sam...@gm...
+This manual page was written by
+.An S.Sam Arun Raj Aq sam...@gm...
+.Sh LIMITATIONS
+Unlike the GNU
+.Nm
+this doesn't support multiple object file formats, only ELF using the
+.Xr elf 3
+and
+.Xr gelf 3
+API's.
Added: projects/strings/trunk/strings.c
===================================================================
--- projects/strings/trunk/strings.c (rev 0)
+++ projects/strings/trunk/strings.c 2008-04-02 09:44:26 UTC (rev 3)
@@ -0,0 +1,411 @@
+/*-
+ * Copyright (c) 2007 S.Sam Arun Raj
+ * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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>
+__FBSDID("$FreeBSD$");
+
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <ctype.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sysexits.h>
+#include <unistd.h>
+
+#include <libelf.h>
+#include <gelf.h>
+
+enum radix_style {
+ RADIX_DECIMAL,
+ RADIX_HEX,
+ RADIX_OCTAL
+};
+
+enum encoding_style {
+ ENCODING_7BIT,
+ ENCODING_8BIT,
+ ENCODING_16BIT_BIG,
+ ENCODING_16BIT_LITTLE,
+ ENCODING_32BIT_BIG,
+ ENCODING_32BIT_LITTLE
+};
+
+#define PRINTABLE(c) \
+ ((c) >= 0 && (c) <= 255 && \
+ ((c) == '\t' || isprint((c)) || \
+ (encoding == ENCODING_8BIT && (c) > 127)))
+
+
+int encoding_size, entire_file, min_len, show_filename, show_loc;
+enum encoding_style encoding;
+enum radix_style radix;
+
+long getcharacter(void);
+int handle_file(const char *);
+int handle_elf(const char *, int);
+int handle_binary(const char *, int);
+int find_strings(const char *, off_t, off_t);
+void usage(void);
+
+/*
+ * strings(1) extracts text(contiguous printable characters)
+ * from elf and binary files.
+ */
+int
+main(int argc, char **argv)
+{
+ int ch, rc;
+
+ rc = EX_OK;
+ min_len = 0;
+ encoding_size = 1;
+ if (elf_version(EV_CURRENT) == EV_NONE)
+ errx(EX_SOFTWARE, "ELF library initialization failed: %s",
+ elf_errmsg(-1));
+
+ while ((ch = getopt(argc, argv, "1234567890ae:fhn:ot:")) != -1)
+ switch((char)ch) {
+ case 'a':
+ entire_file = 1;
+ break;
+ case 'e':
+ if (*optarg == 's') {
+ encoding = ENCODING_7BIT;
+ } else if (*optarg == 'S') {
+ encoding = ENCODING_8BIT;
+ } else if (*optarg == 'b') {
+ encoding = ENCODING_16BIT_BIG;
+ encoding_size = 2;
+ } else if (*optarg == 'B') {
+ encoding = ENCODING_32BIT_BIG;
+ encoding_size = 4;
+ } else if (*optarg == 'l') {
+ encoding = ENCODING_16BIT_LITTLE;
+ encoding_size = 2;
+ } else if (*optarg == 'L') {
+ encoding = ENCODING_32BIT_LITTLE;
+ encoding_size = 4;
+ } else
+ usage();
+ /* NOTREACHED */
+ break;
+ case 'f':
+ show_filename = 1;
+ break;
+ case 'n':
+ min_len = (int)strtoimax(optarg, (char**)NULL, 10);
+ break;
+ case 'o':
+ show_loc = 1;
+ radix = RADIX_OCTAL;
+ break;
+ case 't':
+ show_loc = 1;
+ if (*optarg == 'd')
+ radix = RADIX_DECIMAL;
+ else if (*optarg == 'o')
+ radix = RADIX_OCTAL;
+ else if (*optarg == 'x')
+ radix = RADIX_HEX;
+ else
+ usage();
+ /* NOTREACHED */
+ break;
+ case '0':
+ case '1':
+ case '2':
+ case '3':
+ case '4':
+ case '5':
+ case '6':
+ case '7':
+ case '8':
+ case '9':
+ min_len *= 10;
+ min_len += ch - '0';
+ break;
+ case 'h':
+ case '?':
+ default:
+ usage();
+ /* NOTREACHED */
+ }
+ argc -= optind;
+ argv += optind;
+
+ if (!min_len)
+ min_len = 4;
+ if (!*argv)
+ rc = handle_file("{standard input}");
+ else while (*argv) {
+ rc = handle_file(*argv);
+ argv++;
+ }
+ return(rc);
+}
+
+int
+handle_file(const char *name)
+{
+ int fd, rt;
+
+ if (name == NULL)
+ return(EX_NOINPUT);
+ if (strcmp("{standard input}", name) != 0) {
+ if (freopen(name, "rb", stdin) == NULL) {
+ warnx("'%s': %s", name, strerror(errno));
+ return(EX_NOINPUT);
+ }
+ } else {
+ return find_strings(name, (off_t)0, (off_t)0);
+ }
+
+ fd = fileno(stdin);
+ if (fd < 0)
+ return(EX_NOINPUT);
+ rt = handle_elf(name, fd);
+ return(rt);
+}
+
+/*
+ * Files not understood by handle_elf, will be passed off here and will
+ * treated as a binary file. This would include text file, core dumps ...
+ */
+int
+handle_binary(const char *name, int fd)
+{
+ struct stat buf;
+
+ memset(&buf, 0, sizeof(struct stat));
+ (void) lseek(fd, (off_t)0, SEEK_SET);
+ if (!fstat(fd, &buf))
+ return find_strings(name, (off_t)0, buf.st_size);
+ return(EX_SOFTWARE);
+}
+
+/*
+ * Will analyse a file to see if it ELF, other files including ar(1),
+ * core dumps are passed off and treated as flat binary files. Unlike
+ * GNU size in FreeBSD this routine will not treat ELF object from
+ * different archs as flat binary files(has to overridden using -a).
+ */
+int
+handle_elf(const char *name, int fd)
+{
+ GElf_Ehdr elfhdr;
+ GElf_Shdr shdr;
+ Elf *elf;
+ Elf_Scn *scn;
+ int rc;
+
+ rc = EX_OK;
+ /* If entire file is choosen, treat it as a binary file */
+ if (entire_file)
+ return handle_binary(name, fd);
+
+ (void) lseek(fd, (off_t)0, SEEK_SET);
+ elf = elf_begin(fd, ELF_C_READ, NULL);
+ if (elf_kind(elf) != ELF_K_ELF) {
+ (void) elf_end(elf);
+ return handle_binary(name, fd);
+ }
+
+ if (gelf_getehdr(elf, &elfhdr) == NULL) {
+ (void) elf_end(elf);
+ warnx("%s: ELF file could not be processed", name);
+ return(EX_SOFTWARE);
+ }
+
+ if (elfhdr.e_shnum == 0 && elfhdr.e_type == ET_CORE) {
+ (void) elf_end(elf);
+ return handle_binary(name, fd);
+ } else {
+ scn = NULL;
+ while ((scn = elf_nextscn(elf, scn)) != NULL) {
+ if (gelf_getshdr(scn, &shdr) == NULL)
+ continue;
+ if (shdr.sh_type != SHT_NOBITS &&
+ (shdr.sh_flags & SHF_ALLOC) != 0) {
+ rc = find_strings(name, shdr.sh_offset,
+ shdr.sh_size);
+ }
+ }
+ }
+ (void) elf_end(elf);
+ return(rc);
+}
+
+/*
+ * Retrieves a character from input stream based on the encoding
+ * type requested.
+ */
+long
+getcharacter()
+{
+ long rt;
+ int i;
+ char buf[4], c;
+
+ rt = EOF;
+ for(i = 0; i < encoding_size; i++) {
+ c = getc(stdin);
+ if (feof(stdin))
+ return(EOF);
+ buf[i] = c;
+ }
+
+ switch(encoding) {
+ case ENCODING_7BIT:
+ case ENCODING_8BIT:
+ rt = buf[0];
+ break;
+ case ENCODING_16BIT_BIG:
+ rt = (buf[0] << 8) | buf[1];
+ break;
+ case ENCODING_16BIT_LITTLE:
+ rt = buf[0] | (buf[1] << 8);
+ break;
+ case ENCODING_32BIT_BIG:
+ rt = ((long) buf[0] << 24) | ((long) buf[1] << 16) |
+ ((long) buf[2] << 8) | buf[3];
+ break;
+ case ENCODING_32BIT_LITTLE:
+ rt = buf[0] | ((long) buf[1] << 8) | ((long) buf[2] << 16) |
+ ((long) buf[3] << 24);
+ break;
+ }
+ return(rt);
+}
+
+/*
+ * Input stream stdin is read until the end of file is reached or until
+ * the section size is reached in case of ELF files. Contiguous
+ * characters of >= min_size(default 4) will be displayed.
+ */
+int
+find_strings(const char *name, off_t offset, off_t size)
+{
+ off_t cur_off, start_off;
+ char *obuf;
+ long c;
+ int i;
+
+ if ((obuf = (char*)calloc(1, min_len + 1)) == NULL) {
+ (void) fprintf(stderr, "Unable to allocate memory: %s\n",
+ strerror(errno));
+ return(EX_SOFTWARE);
+ }
+
+ (void) fseeko(stdin, offset, SEEK_SET);
+ cur_off = offset;
+ start_off = 0;
+ while(1) {
+ if ((offset + size) && (cur_off >= offset + size))
+ break;
+ start_off = cur_off;
+ memset(obuf, 0, min_len+1);
+ for(i = 0; i < min_len; i++) {
+ c = getcharacter();
+ if (c == EOF && feof(stdin))
+ goto _exit1;
+ if (PRINTABLE(c)) {
+ obuf[i] = c;
+ obuf[i+1] = 0;
+ cur_off += encoding_size;
+ } else {
+ if (encoding == ENCODING_8BIT &&
+ (uint8_t)c > 127) {
+ obuf[i] = c;
+ obuf[i+1] = 0;
+ cur_off += encoding_size;
+ continue;
+ }
+ cur_off += encoding_size;
+ break;
+ }
+ }
+
+ if (i >= min_len && ((cur_off <= offset + size) ||
+ !(offset + size))) {
+ if (show_filename)
+ printf ("%s: ", name);
+ if (show_loc) {
+ switch(radix) {
+ case RADIX_DECIMAL:
+ (void) printf("%7Ld ",
+ (uint64_t)start_off);
+ break;
+ case RADIX_HEX:
+ (void) printf("%7Lx ",
+ (uint64_t)start_off);
+ break;
+ case RADIX_OCTAL:
+ (void) printf("%7Lo ",
+ (uint64_t)start_off);
+ break;
+ }
+ }
+ printf("%s", obuf);
+
+ while(1) {
+ if ((offset + size) &&
+ (cur_off >= offset + size))
+ break;
+ c = getcharacter();
+ cur_off += encoding_size;
+ if (encoding == ENCODING_8BIT &&
+ (uint8_t)c > 127) {
+ putchar(c);
+ continue;
+ }
+ if (!PRINTABLE(c) || c == EOF)
+ break;
+ putchar(c);
+ }
+ putchar('\n');
+ }
+ }
+_exit1:
+ free(obuf);
+ return(EX_OK);
+}
+
+void
+usage()
+{
+ (void) fprintf(stderr,
+ "strings [-afho] [-e s|S|l|L|b|B] [-n #] [-t o|x|d] file ...\n");
+ exit(EX_USAGE);
+}
+
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