1STRINGS(P) POSIX Programmer's Manual STRINGS(P)
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6 strings - find printable strings in files
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9 strings [-a][-t format][-n number][file...]
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12 The strings utility shall look for printable strings in regular files
13 and shall write those strings to standard output. A printable string is
14 any sequence of four (by default) or more printable characters termi‐
15 nated by a <newline> or NUL character. Additional implementation-
16 defined strings may be written; see localedef.
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19 The strings utility shall conform to the Base Definitions volume of
20 IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
21 The following options shall be supported:
23 -a Scan files in their entirety. If -a is not specified, it is
25 implementation-defined what portion of each file is scanned for
26 strings.
27 -n number
29 Specify the minimum string length, where the number argument is
30 a positive decimal integer. The default shall be 4.
31 -t format
33 Write each string preceded by its byte offset from the start of
34 the file. The format shall be dependent on the single character
35 used as the format option-argument:
36 d
38 The offset shall be written in decimal.
39 o
41 The offset shall be written in octal.
42 x
44 The offset shall be written in hexadecimal.
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49 The following operand shall be supported:
50 file A pathname of a regular file to be used as input. If no file op‐
52 erand is specified, the strings utility shall read from the
53 standard input.
54
57 See the INPUT FILES section.
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60 The input files named by the utility arguments or the standard input
61 shall be regular files of any format.
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64 The following environment variables shall affect the execution of
65 strings:
66 LANG Provide a default value for the internationalization variables
68 that are unset or null. (See the Base Definitions volume of
69 IEEE Std 1003.1-2001, Section 8.2, Internationalization Vari‐
70 ables for the precedence of internationalization variables used
71 to determine the values of locale categories.)
72 LC_ALL If set to a non-empty string value, override the values of all
74 the other internationalization variables.
75 LC_CTYPE
77 Determine the locale for the interpretation of sequences of
78 bytes of text data as characters (for example, single-byte as
79 opposed to multi-byte characters in arguments and input files)
80 and to identify printable strings.
81 LC_MESSAGES
83 Determine the locale that should be used to affect the format
84 and contents of diagnostic messages written to standard error.
85 NLSPATH
87 Determine the location of message catalogs for the processing of
88 LC_MESSAGES .
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92 Default.
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95 Strings found shall be written to the standard output, one per line.
96 When the -t option is not specified, the format of the output shall be:
98 "%s", <string>
101 With the -t o option, the format of the output shall be:
103 "%o %s", <byte offset>, <string>
106 With the -t x option, the format of the output shall be:
108 "%x %s", <byte offset>, <string>
111 With the -t d option, the format of the output shall be:
113 "%d %s", <byte offset>, <string>
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118 The standard error shall be used only for diagnostic messages.
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121 None.
122
124 None.
125
127 The following exit values shall be returned:
128 0 Successful completion.
130 >0 An error occurred.
132
135 Default.
136 The following sections are informative.
138
140 By default the data area (as opposed to the text, "bss", or header
141 areas) of a binary executable file is scanned. Implementations docu‐
142 ment which areas are scanned.
143 Some historical implementations do not require NUL or <newline> termi‐
145 nators for strings to permit those languages that do not use NUL as a
146 string terminator to have their strings written.
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149 None.
150
152 Apart from rationalizing the option syntax and slight difficulties with
153 object and executable binary files, strings is specified to match his‐
154 torical practice closely. The -a and -n options were introduced to
155 replace the non-conforming - and - number options.
156 The -o option historically means different things on different imple‐
158 mentations. Some use it to mean " offset in decimal", while others use
159 it as " offset in octal". Instead of trying to decide which way would
160 be least objectionable, the -t option was added. It was originally
161 named -O to mean "offset", but was changed to -t to be consistent with
162 od.
163 The ISO C standard function isprint() is restricted to a domain of
165 unsigned char. This volume of IEEE Std 1003.1-2001 requires implementa‐
166 tions to write strings as defined by the current locale.
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169 None.
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172 localedef , nm
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175 Portions of this text are reprinted and reproduced in electronic form
176 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
177 -- Portable Operating System Interface (POSIX), The Open Group Base
178 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
179 Electrical and Electronics Engineers, Inc and The Open Group. In the
180 event of any discrepancy between this version and the original IEEE and
181 The Open Group Standard, the original IEEE and The Open Group Standard
182 is the referee document. The original Standard can be obtained online
183 at http://www.opengroup.org/unix/online.html .
184IEEE/The Open Group 2003 STRINGS(P)