bash.0

android-w.song.android.widget

BASH(1)                                                                BASH(1)



NNAAMMEE
       bash - GNU Bourne-Again SHell

SSYYNNOOPPSSIISS
       bbaasshh [options] [file]

CCOOPPYYRRIIGGHHTT
       Bash is Copyright (C) 1989-2010 by the Free Software Foundation, Inc.

DDEESSCCRRIIPPTTIIOONN
       BBaasshh  is  an  sshh-compatible  command language interpreter that executes
       commands read from the standard input or from a file.  BBaasshh also incor-
       porates useful features from the _K_o_r_n and _C shells (kksshh and ccsshh).

       BBaasshh  is  intended  to  be a conformant implementation of the Shell and
       Utilities portion  of  the  IEEE  POSIX  specification  (IEEE  Standard
       1003.1).  BBaasshh can be configured to be POSIX-conformant by default.

OOPPTTIIOONNSS
       All  of  the  single-character shell options documented in the descrip-
       tion of the sseett builtin command can be used as options when  the  shell
       is invoked.  In addition, bbaasshh interprets the following options when it
       is invoked:

       --cc _s_t_r_i_n_g If the --cc option is present,  then  commands  are  read  from
                 _s_t_r_i_n_g.   If  there  are arguments after the _s_t_r_i_n_g, they are
                 assigned to the positional parameters, starting with $$00.
       --ii        If the --ii option is present, the shell is _i_n_t_e_r_a_c_t_i_v_e.
       --ll        Make bbaasshh act as if it had been invoked as a login shell (see
                 IINNVVOOCCAATTIIOONN below).
       --rr        If  the  --rr  option  is present, the shell becomes _r_e_s_t_r_i_c_t_e_d
                 (see RREESSTTRRIICCTTEEDD SSHHEELLLL below).
       --ss        If the --ss option is present, or if no arguments remain  after
                 option  processing,  then commands are read from the standard
                 input.  This option allows the positional  parameters  to  be
                 set when invoking an interactive shell.
       --DD        A  list of all double-quoted strings preceded by $$ is printed
                 on the standard output.  These are the strings that are  sub-
                 ject to language translation when the current locale is not CC
                 or PPOOSSIIXX.  This implies the --nn option; no  commands  will  be
                 executed.
       [[--++]]OO [[_s_h_o_p_t___o_p_t_i_o_n]]
                 _s_h_o_p_t___o_p_t_i_o_n  is  one  of  the  shell options accepted by the
                 sshhoopptt  builtin  (see  SSHHEELLLL  BBUUIILLTTIINN  CCOOMMMMAANNDDSS  below).    If
                 _s_h_o_p_t___o_p_t_i_o_n is present, --OO sets the value of that option; ++OO
                 unsets it.  If _s_h_o_p_t___o_p_t_i_o_n is not supplied,  the  names  and
                 values  of the shell options accepted by sshhoopptt are printed on
                 the standard output.  If the invocation  option  is  ++OO,  the
                 output  is displayed in a format that may be reused as input.
       ----        A ---- signals the end of options and disables  further  option
                 processing.   Any arguments after the ---- are treated as file-
                 names and arguments.  An argument of -- is equivalent to ----.

       BBaasshh also  interprets  a  number  of  multi-character  options.   These
       options  must  appear  on  the command line before the single-character
       options to be recognized.

       ----ddeebbuuggggeerr
              Arrange for the debugger profile to be executed before the shell
              starts.   Turns  on extended debugging mode (see the description
              of the eexxttddeebbuugg option to the sshhoopptt builtin below).
       ----dduummpp--ppoo--ssttrriinnggss
              Equivalent to --DD, but the output is in the GNU _g_e_t_t_e_x_t ppoo  (por-
              table object) file format.
       ----dduummpp--ssttrriinnggss
              Equivalent to --DD.
       ----hheellpp Display  a  usage  message  on standard output and exit success-
              fully.
       ----iinniitt--ffiillee _f_i_l_e
       ----rrccffiillee _f_i_l_e
              Execute commands from _f_i_l_e instead of the standard personal ini-
              tialization  file  _~_/_._b_a_s_h_r_c  if  the  shell is interactive (see
              IINNVVOOCCAATTIIOONN below).

       ----llooggiinn
              Equivalent to --ll.

       ----nnooeeddiittiinngg
              Do not use the GNU rreeaaddlliinnee library to read command  lines  when
              the shell is interactive.

       ----nnoopprrooffiillee
              Do  not read either the system-wide startup file _/_e_t_c_/_p_r_o_f_i_l_e or
              any  of  the  personal  initialization  files   _~_/_._b_a_s_h___p_r_o_f_i_l_e,
              _~_/_._b_a_s_h___l_o_g_i_n,  or  _~_/_._p_r_o_f_i_l_e.   By  default,  bbaasshh reads these
              files when it is  invoked  as  a  login  shell  (see  IINNVVOOCCAATTIIOONN
              below).

       ----nnoorrcc Do  not  read  and  execute  the  personal  initialization  file
              _~_/_._b_a_s_h_r_c if the shell is interactive.  This  option  is  on  by
              default if the shell is invoked as sshh.

       ----ppoossiixx
              Change  the behavior of bbaasshh where the default operation differs
              from the POSIX standard to match the standard (_p_o_s_i_x _m_o_d_e).

       ----rreessttrriicctteedd
              The shell becomes restricted (see RREESSTTRRIICCTTEEDD SSHHEELLLL below).

       ----vveerrbboossee
              Equivalent to  --vv.

       ----vveerrssiioonn
              Show version information for this instance of bbaasshh on the  stan-
              dard output and exit successfully.

AARRGGUUMMEENNTTSS
       If arguments remain after option processing, and neither the --cc nor the
       --ss option has been supplied, the first argument is assumed  to  be  the
       name  of  a file containing shell commands.  If bbaasshh is invoked in this
       fashion, $$00 is set to the name of the file, and the positional  parame-
       ters  are set to the remaining arguments.  BBaasshh reads and executes com-
       mands from this file, then exits.  BBaasshh's exit status is the exit  sta-
       tus  of  the  last  command executed in the script.  If no commands are
       executed, the exit status is 0.  An attempt is first made to  open  the
       file in the current directory, and, if no file is found, then the shell
       searches the directories in PPAATTHH for the script.

IINNVVOOCCAATTIIOONN
       A _l_o_g_i_n _s_h_e_l_l is one whose first character of argument zero is a --,  or
       one started with the ----llooggiinn option.

       An  _i_n_t_e_r_a_c_t_i_v_e  shell  is one started without non-option arguments and
       without the --cc option whose standard input and error are both connected
       to  terminals  (as determined by _i_s_a_t_t_y(3)), or one started with the --ii
       option.  PPSS11 is set and $$-- includes ii if bbaasshh is interactive,  allowing
       a shell script or a startup file to test this state.

       The  following paragraphs describe how bbaasshh executes its startup files.
       If any of the files exist but cannot be read, bbaasshh  reports  an  error.
       Tildes are expanded in file names as described below under TTiillddee EExxppaann--
       ssiioonn in the EEXXPPAANNSSIIOONN section.

       When bbaasshh is invoked as an interactive login shell, or as a  non-inter-
       active  shell with the ----llooggiinn option, it first reads and executes com-
       mands from the file _/_e_t_c_/_p_r_o_f_i_l_e, if that file exists.   After  reading
       that file, it looks for _~_/_._b_a_s_h___p_r_o_f_i_l_e, _~_/_._b_a_s_h___l_o_g_i_n, and _~_/_._p_r_o_f_i_l_e,
       in that order, and reads and executes commands from the first one  that
       exists  and  is  readable.  The ----nnoopprrooffiillee option may be used when the
       shell is started to inhibit this behavior.

       When a login shell exits, bbaasshh reads and  executes  commands  from  the
       file _~_/_._b_a_s_h___l_o_g_o_u_t, if it exists.

       When  an  interactive  shell that is not a login shell is started, bbaasshh
       reads and executes commands from _~_/_._b_a_s_h_r_c, if that file exists.   This
       may  be inhibited by using the ----nnoorrcc option.  The ----rrccffiillee _f_i_l_e option
       will force bbaasshh to read and  execute  commands  from  _f_i_l_e  instead  of
       _~_/_._b_a_s_h_r_c.

       When  bbaasshh  is  started  non-interactively,  to run a shell script, for
       example, it looks for the variable BBAASSHH__EENNVV in the environment, expands
       its  value if it appears there, and uses the expanded value as the name
       of a file to read and execute.  BBaasshh behaves as if the  following  com-
       mand were executed:
              if [ -n "$BASH_ENV" ]; then . "$BASH_ENV"; fi
       but  the  value of the PPAATTHH variable is not used to search for the file
       name.

       If bbaasshh is invoked with the name sshh, it  tries  to  mimic  the  startup
       behavior  of  historical  versions  of sshh as closely as possible, while
       conforming to the POSIX standard as well.  When invoked as an  interac-
       tive  login  shell, or a non-interactive shell with the ----llooggiinn option,
       it first attempts to read and execute commands  from  _/_e_t_c_/_p_r_o_f_i_l_e  and
       _~_/_._p_r_o_f_i_l_e,  in  that  order.   The  ----nnoopprrooffiillee  option may be used to
       inhibit this behavior.  When invoked as an interactive shell  with  the
       name  sshh,  bbaasshh  looks for the variable EENNVV, expands its value if it is
       defined, and uses the expanded value as the name of a file to read  and
       execute.  Since a shell invoked as sshh does not attempt to read and exe-
       cute commands from any other startup files, the ----rrccffiillee option has  no
       effect.   A  non-interactive  shell  invoked  with the name sshh does not
       attempt to read any other startup files.   When  invoked  as  sshh,  bbaasshh
       enters _p_o_s_i_x mode after the startup files are read.

       When  bbaasshh  is  started in _p_o_s_i_x mode, as with the ----ppoossiixx command line
       option, it follows the POSIX standard for startup files.  In this mode,
       interactive  shells  expand  the EENNVV variable and commands are read and
       executed from the file whose name is  the  expanded  value.   No  other
       startup files are read.

       BBaasshh attempts to determine when it is being run with its standard input
       connected to a network connection, as when executed by the remote shell
       daemon,  usually _r_s_h_d, or the secure shell daemon _s_s_h_d.  If bbaasshh deter-
       mines it is being run in this fashion, it reads and  executes  commands
       from  _~_/_._b_a_s_h_r_c,  if  that file exists and is readable.  It will not do
       this if invoked as sshh.  The ----nnoorrcc option may be used to  inhibit  this
       behavior,  and the ----rrccffiillee option may be used to force another file to
       be read, but _r_s_h_d does  not  generally  invoke  the  shell  with  those
       options or allow them to be specified.

       If the shell is started with the effective user (group) id not equal to
       the real user (group) id, and the --pp option is not supplied, no startup