python - The message packer reads a string

The message packer reads a string

You need to implement a Message Packer. The message packer reads a string

Rules:

• adds two chars ZZ to mark the beginning of the message
• add number 0 to mark the end of the message.
• The input string is reversed inside the message.
• If the input string contains char Z then it is replaced by # in the message. The lower case character z is retained
• If the input string contains numeric character 0 then it is replaced by $.
• Only lower case letter ([a-z]), upper case letter ([A-Z]) and numeric characters ([0-9]) are accepted. If the string contains any other characters an error message Invalid String
• Maximum number of characters accepted in the string is 8. If the number exceeds 8 then Exceeded Limit   is output

Sample:

• Input : You need to read a string from STDIN.
• Output :  Message Packed as per rules above or Invalid String or Exceeded Limit is  printed.
• 
  
• Input: PQRS
• Output: ZZSRQP0
• 
  
• Input: ABbcZdz
• Output: ZZzd#cbBA0
• 
  
• Input: X1340yZ
• Output: ZZ#y$431X0
• 
  
• Input: AB*D1$34
• Output: Invalid String
• 
  
• Input: ABCD12345
• Output: Exceeded Limit

Program:

def main():

    message = raw_input("Enter value :")

    count = 0

    reverse = ''.join(reversed(message))    # Reversed the string , must need join

    lis = list(reverse)          # Reverse the string

    lengh = len(reverse)

    if lengh > 8:                # Length should be less than 8

        print "Exceeded Limit"

        return

    count = 0

    for char in lis:

        if char == 'Z':

            lis[count] = '#'

        elif char == '0':

            lis[count] = '$'

        elif not (char.isupper() or char.islower() or char.isdigit()):

            print "Invalid String"

            return

        count = count + 1

    lis.append('0')

    lis = ['Z'] + lis                 # Append the Z to the begging of the list

    lis = ['Z'] + lis

    result = ''.join(lis)            # Convert list to the string

    print result

main()

Output:

acp_python$ python messagePacker.py

Enter value :ABbcZdz

ZZzd#cbBA0

acp_python$ vi messagePacker.py

acp_python$ python messagePacker.py

Enter value :X1340yZ

ZZ#y$431X0

acp_python$ python messagePacker.py

Enter value :AB*D1$34

Invalid String

acp_python$ python messagePacker.py

Enter value :ABCD12345

Exceeded Limit

python - Password validity checker using python

Password validity checker using python

• You need to implement a password validity checker.  A password is valid if all the given rules are satisfied, else it is invalid.
•  At least 1 (one) lower case letter ([a-z]) is present
•  At least 1 numeric character ([0-9]) is present  
•  At least 1 (one) upper  case letter ([A-Z]) is present
•  At least 1 character from [$#@] is present
•  Minimum and Maximum length allowed must be 6 and 12 respectively
• Input : You need to read a string from STDIN and check if it is a valid or invalid password.
• Output : The string valid or invalid printed.

• Test Cases:

• Input: ABCDa$$$$$56
• Output: valid
• 
  
• Input: 12345abcd111
• Output: invalid

• Input: 2w3E*
• Output: invalid

Program:

def main():

    password = raw_input("Enter value :")

    digit = 0

    upper = 0

    lower = 0

    special = 0

    flag_len = 0

    for char in password:

        if char.isdigit():

            digit = 1

        if char.isupper():

            upper = 1

        if char.islower():

            lower = 1

        if char == '$' or  char == '#' or char == '@':

            special = 1

    length = len(password)

    if length >= 6 and length <= 12:

        flag_len = 1

    if digit and upper and lower and special and flag_len:

       print "valid"

    else:

       print "invalid"

main()

Output:

python$ python passwordVali.py

Enter value :Velraj

invalid

python$

python$

python$ python passwordVali.py

Enter value :Velraj12#

valid

how to run system command in c

how to run system command in c

• Use system( ) to run the command if input and output are not important.
• Use popen( ) if control on either input or output is needed.

System:

• system() is used to invoke an operating system command from a C/C++ program.
• int system(const char *command);
• stdlib.h  is needed

• Using system(), we can execute any command that can run on terminal if operating system allows. 
• For example, we can call system(“dir”) on Windows and system(“ls”) to list contents of a directory.

Example Program:

#include <stdio.h>

#include <string.h>

int main () {

    char command[256];

    strcpy( command, "ls -l" );

    system(command);

   

    return 0;

}

Output:

sample$ ./a.out

total 156

-rw-rw-r-- 1 labuser labuser     159 Dec 18 21:59 '

-rw-rw-r-- 1 labuser labuser     338 Aug  3  2017 ]

-rw-rw-r-- 1 labuser labuser    1035 May 16  2017 access.c

-rwxrwxr-x 1 labuser labuser    8688 Apr 23 21:52 a.out

-rw-rw-r-- 1 labuser labuser     231 May 16  2017 array_init.c

-rw-rw-r-- 1 labuser labuser     585 May 19  2017 array_size.c

-rw-rw-r-- 1 labuser labuser     347 Aug 30  2017 assert.c

-rw-rw-r-- 1 labuser labuser     992 Jan 31 21:14 backtrace.c

How to use gprof to generate gmon.out while running the program

How to use gprof to generate gmon.out while running the program

• The function "monstartup" is used to reinitialize the data block used by gmon to collect profile data.
• The function "_mcleanup"  writes profile data to gmon.out
• Change the current direct to /tmp to place the gmon.out to the default folder /tmop
• After finish the test revert the current folder.
• Send the SIGUSR2  signal to the process to generate the gmon.out file.
• Generate the gmon.out file
• send the signal using below
• $kill -s SIGUSR2 26908
• See the output in below folder
• $cd /tmp

Example Program:

Program file 1: gprof_test-signal.c

#include<stdio.h>

#include<stdlib.h>

#include <dirent.h>

#include <sys/gmon.h>

#include <signal.h>

#include <string.h>

void write_gmon_out_file();

void sigusr2_handler(int sig);

void gprof_init(void);

/* Beginning and end of our code segment.  */

extern void _start (void), etext (void);

/*

 * This function uses APIs from the gmon library which is part of the

 * the standard glibC library, to force write the profile data.

 * The function "monstartup" is used to reinitialize the data block

 * used by gmon to collect profile data.

 * The function "_mcleanup"  writes profile data to gmon.out

 */

void write_gmon_out_file (void)

{

    char *gmon_dir = "/tmp";

    char originalDir[256];

    if (getcwd(originalDir, 256) == '\0') {

        printf("Failed to get original working directory... \n");

        memset(originalDir, 0, 256);

    }

    else {

        printf("Original Dir = %s \n", originalDir);

    }

    if (chdir(gmon_dir) == 0) {

        printf("Successfully changed to dir = %s \n", gmon_dir);

    }

    else {

        printf("Failed to change to dir = %s \n", gmon_dir);

    }

    _mcleanup();

    monstartup((unsigned long ) &_start, (unsigned long ) &etext);

    if (originalDir[0] != 0) {

        printf("Switching to original working dir ...\n");

        chdir(originalDir);

    }

    return ;

}

void sigusr2_handler(int sig)

{

    printf("Received Signal: %d\n", sig);

    write_gmon_out_file() ;

    signal(SIGUSR2, sigusr2_handler) ;

}

void gprof_init(void)

{

    signal(SIGUSR2, sigusr2_handler) ;

    printf("GPROF SIGNAL HANDLER INITIALIZED\r\n");

    sleep(5);

}

void new_func1(void);

void func1(void)

{

    printf("\n Inside func1 \n");

    int i = 0;

    //exit(0);

    sleep(10);

    for(;i<0xffffffff;i++);

    new_func1();

    return;

}

static void func2(void)

{

    printf("\n Inside func2 \n");

    int i = 0;

    for(;i<0xffffffaa;i++);

    return;

}

int main(void)

{

    printf("\n Inside main()\n");

    int i = 0;

     gprof_init();

    for(;i<0xffffff;i++);

    func1();

    func2();

    return 0;

}

Program 2: gprof_test_2.c

//test_gprof_new.c

#include<stdio.h>

void new_func1(void)

{

    printf("\n Inside new_func1()\n");

    int i = 0;

    for(;i<0xffffffee;i++);

    return;

}

Output:

Execute the program:

gprof$ ./a.out

 Inside main()

GPROF SIGNAL HANDLER INITIALIZED

 Inside func1

Received Signal: 12

Original Dir = /home/labuser/velrajk/sample/gprof

Successfully changed to dir = /tmp

Switching to original working dir ...

---- output file.

$cd /tmp

$ ls gmon.out 

gmon.out

$