EXPAND(1)                  POSIX Programmer's Manual                 EXPAND(1)



PPRROOLLOOGG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NNAAMMEE
       expand -- convert tabs to spaces

SSYYNNOOPPSSIISS
       expand [[-t _t_a_b_l_i_s_t]] [[_f_i_l_e...]]

DDEESSCCRRIIPPTTIIOONN
       The _e_x_p_a_n_d utility shall write files or the standard input to the
       standard output with <tab> characters replaced with one or more <space>
       characters needed to pad to the next tab stop. Any <backspace>
       characters shall be copied to the output and cause the column position
       count for tab stop calculations to be decremented; the column position
       count shall not be decremented below zero.

OOPPTTIIOONNSS
       The _e_x_p_a_n_d utility shall conform to the Base Definitions volume of
       POSIX.1-2017, _S_e_c_t_i_o_n _1_2_._2, _U_t_i_l_i_t_y _S_y_n_t_a_x _G_u_i_d_e_l_i_n_e_s.

       The following option shall be supported:

       --tt _t_a_b_l_i_s_t
                 Specify the tab stops. The application shall ensure that the
                 argument _t_a_b_l_i_s_t consists of either a single positive decimal
                 integer or a list of tabstops. If a single number is given,
                 tabs shall be set that number of column positions apart
                 instead of the default 8.

                 If a list of tabstops is given, the application shall ensure
                 that it consists of a list of two or more positive decimal
                 integers, separated by <blank> or <comma> characters, in
                 ascending order. The <tab> characters shall be set at those
                 specific column positions. Each tab stop _N shall be an
                 integer value greater than zero, and the list is in strictly
                 ascending order. This is taken to mean that, from the start
                 of a line of output, tabbing to position _N shall cause the
                 next character output to be in the (_N+1)th column position on
                 that line.

                 In the event of _e_x_p_a_n_d having to process a <tab> at a
                 position beyond the last of those specified in a multiple
                 tab-stop list, the <tab> shall be replaced by a single
                 <space> in the output.

OOPPEERRAANNDDSS
       The following operand shall be supported:

       _f_i_l_e      The pathname of a text file to be used as input.

SSTTDDIINN
       See the INPUT FILES section.

IINNPPUUTT FFIILLEESS
       Input files shall be text files.

EENNVVIIRROONNMMEENNTT VVAARRIIAABBLLEESS
       The following environment variables shall affect the execution of
       _e_x_p_a_n_d:

       _L_A_N_G      Provide a default value for the internationalization
                 variables that are unset or null. (See the Base Definitions
                 volume of POSIX.1-2017, _S_e_c_t_i_o_n _8_._2, _I_n_t_e_r_n_a_t_i_o_n_a_l_i_z_a_t_i_o_n
                 _V_a_r_i_a_b_l_e_s for the precedence of internationalization
                 variables used to determine the values of locale categories.)

       _L_C___A_L_L    If set to a non-empty string value, override the values of
                 all the other internationalization variables.

       _L_C___C_T_Y_P_E  Determine the locale for the interpretation of sequences of
                 bytes of text data as characters (for example, single-byte as
                 opposed to multi-byte characters in arguments and input
                 files), the processing of <tab> and <space> characters, and
                 for the determination of the width in column positions each
                 character would occupy on an output device.

       _L_C___M_E_S_S_A_G_E_S
                 Determine the locale that should be used to affect the format
                 and contents of diagnostic messages written to standard
                 error.

       _N_L_S_P_A_T_H   Determine the location of message catalogs for the processing
                 of _L_C___M_E_S_S_A_G_E_S.

AASSYYNNCCHHRROONNOOUUSS EEVVEENNTTSS
       Default.

SSTTDDOOUUTT
       The standard output shall be equivalent to the input files with <tab>
       characters converted into the appropriate number of <space> characters.

SSTTDDEERRRR
       The standard error shall be used only for diagnostic messages.

OOUUTTPPUUTT FFIILLEESS
       None.

EEXXTTEENNDDEEDD DDEESSCCRRIIPPTTIIOONN
       None.

EEXXIITT SSTTAATTUUSS
       The following exit values shall be returned:

        0    Successful completion

       >0    An error occurred.

CCOONNSSEEQQUUEENNCCEESS OOFF EERRRROORRSS
       The _e_x_p_a_n_d utility shall terminate with an error message and non-zero
       exit status upon encountering difficulties accessing one of the _f_i_l_e
       operands.

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       None.

EEXXAAMMPPLLEESS
       None.

RRAATTIIOONNAALLEE
       The _e_x_p_a_n_d utility is useful for preprocessing text files (before
       sorting, looking at specific columns, and so on) that contain <tab>
       characters.

       See the Base Definitions volume of POSIX.1-2017, _S_e_c_t_i_o_n _3_._1_0_3, _C_o_l_u_m_n
       _P_o_s_i_t_i_o_n.

       The _t_a_b_l_i_s_t option-argument consists of integers in ascending order.
       Utility Syntax Guideline 8 mandates that _e_x_p_a_n_d shall accept the
       integers (within the single argument) separated using either <comma> or
       <blank> characters.

       Earlier versions of this standard allowed the following form in the
       SYNOPSIS:


           expand [[-tabstop]][[-tab1,tab2,...,tabn]][[_f_i_l_e ...]]

       This form is no longer specified by POSIX.1-2008 but may be present in
       some implementations.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _t_a_b_s, _u_n_e_x_p_a_n_d

       The Base Definitions volume of POSIX.1-2017, _S_e_c_t_i_o_n _3_._1_0_3, _C_o_l_u_m_n
       _P_o_s_i_t_i_o_n, _C_h_a_p_t_e_r _8, _E_n_v_i_r_o_n_m_e_n_t _V_a_r_i_a_b_l_e_s, _S_e_c_t_i_o_n _1_2_._2, _U_t_i_l_i_t_y
       _S_y_n_t_a_x _G_u_i_d_e_l_i_n_e_s

CCOOPPYYRRIIGGHHTT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  In the event of any discrepancy between this version and the
       original IEEE and The Open Group Standard, the original IEEE and The
       Open Group Standard is the referee document. The original Standard can
       be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                            EXPAND(1)
