1TRUE(1P)                   POSIX Programmer's Manual                  TRUE(1P)
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PROLOG

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.
10

NAME

12       true — return true value
13

SYNOPSIS

15       true
16

DESCRIPTION

18       The true utility shall return with exit code zero.
19

OPTIONS

21       None.
22

OPERANDS

24       None.
25

STDIN

27       Not used.
28

INPUT FILES

30       None.
31

ENVIRONMENT VARIABLES

33       None.
34

ASYNCHRONOUS EVENTS

36       Default.
37

STDOUT

39       Not used.
40

STDERR

42       Not used.
43

OUTPUT FILES

45       None.
46

EXTENDED DESCRIPTION

48       None.
49

EXIT STATUS

51       Zero.
52

CONSEQUENCES OF ERRORS

54       None.
55
56       The following sections are informative.
57

APPLICATION USAGE

59       This utility is typically used in shell scripts, as shown in the  EXAM‐
60       PLES  section.  The  special built-in utility : is sometimes more effi‐
61       cient than true.
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EXAMPLES

64       This command is executed forever:
65
66
67           while true
68           do
69               command
70           done
71

RATIONALE

73       The true utility has been retained in this volume of POSIX.1‐2017, even
74       though  the  shell  special  built-in : provides similar functionality,
75       because true is widely used in historical scripts and is  less  cryptic
76       to novice script readers.
77

FUTURE DIRECTIONS

79       None.
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SEE ALSO

82       Section 2.9, Shell Commands, false
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85       Portions  of  this text are reprinted and reproduced in electronic form
86       from IEEE Std 1003.1-2017, Standard for Information Technology --  Por‐
87       table  Operating System Interface (POSIX), The Open Group Base Specifi‐
88       cations Issue 7, 2018 Edition, Copyright (C) 2018 by the  Institute  of
89       Electrical  and  Electronics Engineers, Inc and The Open Group.  In the
90       event of any discrepancy between this version and the original IEEE and
91       The  Open Group Standard, the original IEEE and The Open Group Standard
92       is the referee document. The original Standard can be  obtained  online
93       at http://www.opengroup.org/unix/online.html .
94
95       Any  typographical  or  formatting  errors that appear in this page are
96       most likely to have been introduced during the conversion of the source
97       files  to  man page format. To report such errors, see https://www.ker‐
98       nel.org/doc/man-pages/reporting_bugs.html .
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102IEEE/The Open Group                  2017                             TRUE(1P)
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