1STRINGS(1P) POSIX Programmer's Manual STRINGS(1P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
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12 strings - find printable strings in files
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15 strings [-a][-t format][-n number][file...]
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18 The strings utility shall look for printable strings in regular files
19 and shall write those strings to standard output. A printable string is
20 any sequence of four (by default) or more printable characters termi‐
21 nated by a <newline> or NUL character. Additional implementation-
22 defined strings may be written; see localedef.
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25 The strings utility shall conform to the Base Definitions volume of
26 IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
27 The following options shall be supported:
29 -a Scan files in their entirety. If -a is not specified, it is
31 implementation-defined what portion of each file is scanned for
32 strings.
33 -n number
35 Specify the minimum string length, where the number argument is
36 a positive decimal integer. The default shall be 4.
37 -t format
39 Write each string preceded by its byte offset from the start of
40 the file. The format shall be dependent on the single character
41 used as the format option-argument:
42 d
44 The offset shall be written in decimal.
45 o
47 The offset shall be written in octal.
48 x
50 The offset shall be written in hexadecimal.
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55 The following operand shall be supported:
56 file A pathname of a regular file to be used as input. If no file op‐
58 erand is specified, the strings utility shall read from the
59 standard input.
60
63 See the INPUT FILES section.
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66 The input files named by the utility arguments or the standard input
67 shall be regular files of any format.
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70 The following environment variables shall affect the execution of
71 strings:
72 LANG Provide a default value for the internationalization variables
74 that are unset or null. (See the Base Definitions volume of
75 IEEE Std 1003.1-2001, Section 8.2, Internationalization Vari‐
76 ables for the precedence of internationalization variables used
77 to determine the values of locale categories.)
78 LC_ALL If set to a non-empty string value, override the values of all
80 the other internationalization variables.
81 LC_CTYPE
83 Determine the locale for the interpretation of sequences of
84 bytes of text data as characters (for example, single-byte as
85 opposed to multi-byte characters in arguments and input files)
86 and to identify printable strings.
87 LC_MESSAGES
89 Determine the locale that should be used to affect the format
90 and contents of diagnostic messages written to standard error.
91 NLSPATH
93 Determine the location of message catalogs for the processing of
94 LC_MESSAGES .
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98 Default.
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101 Strings found shall be written to the standard output, one per line.
102 When the -t option is not specified, the format of the output shall be:
104 "%s", <string>
107 With the -t o option, the format of the output shall be:
109 "%o %s", <byte offset>, <string>
112 With the -t x option, the format of the output shall be:
114 "%x %s", <byte offset>, <string>
117 With the -t d option, the format of the output shall be:
119 "%d %s", <byte offset>, <string>
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124 The standard error shall be used only for diagnostic messages.
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127 None.
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130 None.
131
133 The following exit values shall be returned:
134 0 Successful completion.
136 >0 An error occurred.
138
141 Default.
142 The following sections are informative.
144
146 By default the data area (as opposed to the text, "bss", or header
147 areas) of a binary executable file is scanned. Implementations docu‐
148 ment which areas are scanned.
149 Some historical implementations do not require NUL or <newline> termi‐
151 nators for strings to permit those languages that do not use NUL as a
152 string terminator to have their strings written.
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155 None.
156
158 Apart from rationalizing the option syntax and slight difficulties with
159 object and executable binary files, strings is specified to match his‐
160 torical practice closely. The -a and -n options were introduced to
161 replace the non-conforming - and - number options.
162 The -o option historically means different things on different imple‐
164 mentations. Some use it to mean " offset in decimal", while others use
165 it as " offset in octal". Instead of trying to decide which way would
166 be least objectionable, the -t option was added. It was originally
167 named -O to mean "offset", but was changed to -t to be consistent with
168 od.
169 The ISO C standard function isprint() is restricted to a domain of
171 unsigned char. This volume of IEEE Std 1003.1-2001 requires implementa‐
172 tions to write strings as defined by the current locale.
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175 None.
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178 localedef, nm
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181 Portions of this text are reprinted and reproduced in electronic form
182 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
183 -- Portable Operating System Interface (POSIX), The Open Group Base
184 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
185 Electrical and Electronics Engineers, Inc and The Open Group. In the
186 event of any discrepancy between this version and the original IEEE and
187 The Open Group Standard, the original IEEE and The Open Group Standard
188 is the referee document. The original Standard can be obtained online
189 at http://www.opengroup.org/unix/online.html .
190IEEE/The Open Group 2003 STRINGS(1P)