2.9BSD/usr/man/cat3/system.3

SYSTEM(3)           UNIX Programmer's Manual            SYSTEM(3)

NAME
     system - issue a shell command

SYNTAX
     C:  system(string)
         char *string;

     F:  call system(string,return)
          character*? string
          integer*2 return

DESCRIPTION
     _s_y_s_t_e_m causes the _s_t_r_i_n_g to be given to _s_h(1) as input as if
     the string had been typed as a command at a terminal.  The
     current process waits until the shell has completed, then
     returns the exit status of the shell.

SEE ALSO
     pkopen(3), exec(2), wait(2)

DIAGNOSTICS
     Exit status 127 indicates the shell couldn't be executed.

EXAMPLE
           character*20 name
           call system("pwd",i)
           write(6,1)i
         1 format("    System returns",i5)
           name="print it"
           call system(name,i)
           write(6,1)i
           name="pwd" // "\0"
           call system(name,i)
           write(6,1)i
           end

     Results in:

          /usr/src/libF77
              System returns    0
          print: can't open it
              System returns  512
          /usr/src/libF77
              System returns    0

         char name[] = "pwd";

         main()
         {
             int returns;
             returns = system(name);

Printed 12/7/82                                                 1

SYSTEM(3)           UNIX Programmer's Manual            SYSTEM(3)

                 printf("    System returns %d.\n",returns);
             returns = system("cd ..;pwd");
                 printf("    System returns %d.\n",returns);
             returns = system("pwd");
                 printf("    System returns %d.\n",returns);
         }

     Results in:

         /usr/src/libF77
             System returns 0.
         /usr/src
             System returns 0.
         /usr/src/libF77
             System returns 0.

     Note that changing a directory within system affects only
     that call to system.

Printed 12/7/82                                                 2