system                 package:base                 R Documentation

_I_n_v_o_k_e _a _S_y_s_t_e_m _C_o_m_m_a_n_d

_D_e_s_c_r_i_p_t_i_o_n:

     'system' invokes the OS command specified by 'command'.

_U_s_a_g_e:

     system(command, intern = FALSE, ignore.stderr = FALSE)

_A_r_g_u_m_e_n_t_s:

 command: the system command to be invoked, as a string.

  intern: a logical (not 'NA') which indicates whether to  make the
          output of the command an R object.  Not available unless
          'popen' is supported on the platform.

ignore.stderr: a logical indicating whether error messages (written to
          'stderr') should be ignored.

_D_e_t_a_i_l_s:

     If 'intern' is 'TRUE' then 'popen' is used to invoke the command
     and the output collected, line by line, into an R 'character'
     vector which is returned as the value of 'system'.  Output lines
     of more than 8095 characters will be split.

     If 'intern' is 'FALSE' then the C function 'system' is used to
     invoke the command and the value returned by 'system' is the exit
     status of this function.

     'unix' is a _deprecated_ alternative, available for backwards
     compatibility.

_V_a_l_u_e:

     If 'intern=TRUE', a character vector giving the output of the
     command, one line per character string. If the command could not
     be run or gives an error a R error is generated.

     If 'intern=FALSE', the return value is an error code.

_S_e_e _A_l_s_o:

     '.Platform' for platform specific variables.

_E_x_a_m_p_l_e_s:

     # list all files in the current directory using the -F flag
     ## Not run: system("ls -F")

     # t1 is a character vector, each one
     # representing a separate line of output from who
     # (if the platform has popen and who)
     t1 <- try(system("who", TRUE))

     try(system("ls fizzlipuzzli", TRUE, TRUE))
     # empty since file doesn't exist

