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Annotation of coherent/a/usr/man/ALL/goto, revision 1.1

1.1     ! root        1: 
        !             2: 
        !             3: goto                        C Keyword                        goto
        !             4: 
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        !             7: 
        !             8: Unconditionally jump within a function
        !             9: 
        !            10: 
        !            11: A goto command  jumps to the area of the  program introduced by a
        !            12: label.  A program can goto only within a function; to jump across
        !            13: function  boundaries,  you  must  use  the functions  setjmp  and
        !            14: longjmp.
        !            15: 
        !            16: In the context of C programming,  the most common use for goto is
        !            17: to exit from a control block or go to the top of a control block.
        !            18: It  is  used  most often  to  write  ``ripcord'' routines,  i.e.,
        !            19: routines that are executed  when an major error occurs too deeply
        !            20: within  a function  for the  program  to disentangle  itself cor-
        !            21: rectly.  Note that in most instances, goto is a bad solution to a
        !            22: problem that can be better solved by structured programming.
        !            23: 
        !            24: ***** Example *****
        !            25: 
        !            26: The following example demonstrates how to use goto.
        !            27: 
        !            28: 
        !            29: #include <stdio.h>
        !            30: 
        !            31: 
        !            32: 
        !            33: main()
        !            34: {
        !            35:         char line[80];
        !            36: 
        !            37: 
        !            38: 
        !            39: getline:
        !            40:         printf("Enter line: ");
        !            41:         fflush(stdout);
        !            42:         gets(line);
        !            43: 
        !            44: 
        !            45: 
        !            46: /* a series of tests often is best done with goto's */
        !            47:         if (*line == 'x') {
        !            48:                 printf("Bad line\n");
        !            49:                 goto getline;
        !            50:         } else if (*line == 'y') {
        !            51:                 printf("Try again\n");
        !            52:                 goto getline;
        !            53:         } else if (*line == 'q')
        !            54:                 goto goodbye;
        !            55:         else
        !            56:                 goto getline;
        !            57: 
        !            58: 
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        !            62: 
        !            63: 
        !            64: COHERENT Lexicon                                           Page 1
        !            65: 
        !            66: 
        !            67: 
        !            68: 
        !            69: goto                        C Keyword                        goto
        !            70: 
        !            71: 
        !            72: 
        !            73: goodbye:
        !            74:         printf("Goodbye.\n");
        !            75:         exit(0);
        !            76: }
        !            77: 
        !            78: 
        !            79: ***** See Also *****
        !            80: 
        !            81: C keywords
        !            82: 
        !            83: ***** Notes *****
        !            84: 
        !            85: _T_h_e _C  _P_r_o_g_r_a_m_m_i_n_g _L_a_n_g_u_a_g_e describes  goto as ``infinitely-abus-
        !            86: able'': caveat utilitor.
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        !           130: COHERENT Lexicon                                           Page 2
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