c program that accepts and executes commands?

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    Thumbs up c program that accepts and executes commands?

    You are required to write an interactive C program that prompts the user for commands, accepts
    commands from the keyboard (stdin) and executes those commands, The program must continue
    to accept and process commands until the user types the end command.
    The program maintains a linked list. Each node of the list contains an integer value and a
    pointer to the next node of the list. Note that the same integer value may appear several times
    in the list. At all times, the values in the list must be in non-decreasing order. Some commands
    require your program to modify the list while others involve traversing the list to gather information.
    Initially, the list is empty. The commands and their meanings are as follows. (You should bear in
    mind that different parts of a command are separated by one or more spaces or tabs.)
    (a) Insert Command: The syntax for this command is as follows:
    ins value
    In the above, ins represents the name of the command and value represents an integer value (which
    may be positive, negative or zero). In response to this command, your program should create a
    new node containing the specified value and insert the node into the list in such a way that the
    values in the list continue to be in non-decreasing order even after the insert operation.
    (b) Delete Command: The syntax for this command is as follows:
    del value
    As in the insert command, value represents an integer value (which may be positive, negative or
    zero). In response to this command, your program should delete a node containing the specified
    value from the list, if the list contains such a node. Otherwise, the program should print a short
    message such as “The given value is not in the list”. The same message should be produced even
    when the list is empty. Note that if there are two or more nodes that contain the specified value,
    the delete command should only delete one of the nodes.
    1
    (c) Print List Command: The syntax for this command is as follows:
    pri
    In response to this command, your program should traverse the list and print the value stored in
    each node. (Thus, the number of values printed is equal to the number of nodes in the list.) If the
    list is empty, the output should be a short message such as “The list is empty”.
    (d) Count Command: The syntax for this command is as follows:
    cnt
    In response to this command, your program should output the number of nodes in the list. (If the
    list is empty, the output must be 0.)
    (e) Count Distinct Values Command: The syntax for this command is as follows:
    cdv
    Recall that values may occur multiple times in the list. In response to the cdv command, your
    program should compute and output the number of distinct values in the list. (If the list is empty,
    the output must be 0.)
    Example: To see the difference between the cnt and cdv commands, consider the following list.
    head
    1 5 5 5 7 7 /
    Figure 1: An example of a linked list
    For the above list, the cnt command must output the value 6 (since there are six nodes in the list)
    while the cdv command must output the value 3 (since there are only three distinct values in the
    list, namely 1, 5 and 7).
    (f) Count Occurrences Command: The syntax for this command is as follows:
    occ value
    As in the insert command, value represents an integer value (which may be positive, negative or
    zero). In response to this command, your program should print the number of times the specified
    value occurs in the list (i.e., the number of nodes that contain the specified value). If the value
    does not appear in the list (this also covers the case of an empty list), the answer produced must
    be 0. (For example, in the list shown in Figure 1, the value 5 appears three times while the value
    −7 appears zero times.)
    2
    (g) Count Range Command: The syntax for this command is as follows:
    ran value1 value2
    Here, value1 and value2 represent integer values (which may be positive, negative or zero). Your
    program should first check and make sure that the first value is less than or equal to the second
    value. If this condition is not satisfied, your program should simply print a message of the form
    “Invalid range” and prompt the user for the next command. If the condition is satisfied, then
    your program should compute and print the number of nodes in the list which contain values in
    the range [value1 .. value2]. Note that the range includes both the end points. If none of the
    the values in the range appears in the list (this also covers the case of an empty list), the answer
    produced must be 0. (For example, in the list shown in Figure 1, there are six nodes with values
    in the range [−1 .. 10], five nodes with values in the range [5 .. 7] and zero nodes with values in the
    range [−3 .. 0].)
    (h) End Command: The syntax for this command is as follows:
    end
    In response to this command, your program should stop.
    Note: In writing this program, you may assume the following.
    (a) The command given by the user will be one of ins, del, pri, cnt, cdv, occ or ran. (The
    command names are case sensitive.)
    (b) Each command will contain the appropriate number of integer values (if needed).
    Thus, the only error that your program needs to detect is in the ran command described above.
    Your program should continue to prompt the user and process commands until the user types the
    end command.
    ***********************************************
    Code:
    Program Outline: An outline for your program is as follows.
    1. Prompt the user for a command.
    2. Read the command.
    3. while (command is not "end") {
    (a) Read the value(s) for the command, if necessary.
    (b) Process the command.
    (c) Prompt the user for the next command.
    (d) Read the next command.
    }
    3
    Suggestions:
    1. Write a separate function to implement each command (except end).
    2. Use the "%s" format to read the command as a string into a character array of size 4. (Since
    each command is exactly three characters long and each string must be properly terminated
    using the ’\0’ character, the size of the character array must be 4.)
    3. Use the strcmp function in the string library (<string.h>) to identify which command is
    specified. (

  2. #2
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    What have you tried so far?

  3. #3
    DESTINY BEN10's Avatar
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    @OP
    Nobody will even read it like me. So, come up with specific queries.
    HOPE YOU UNDERSTAND.......

    By associating with wise people you will become wise yourself
    It's fine to celebrate success but it is more important to heed the lessons of failure
    We've got to put a lot of money into changing behavior


    PC specifications- 512MB RAM, Windows XP sp3, 2.79 GHz pentium D.
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  4. #4
    a_capitalist_story
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    There is no "query," it's a straight "here's my homework, now do it for me" post. It's also here and on RentACoder.

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