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How to find the first character in a C++ string


How to find the first character in a C++ string

By : yassin bagane
Date : October 21 2020, 11:12 PM
wish help you to fix your issue See std::string::find_first_not_of.
To find the position (index) of the first non-space character:
code :


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System Calls - How to find a character within a string, if he character exists

System Calls - How to find a character within a string, if he character exists


By : Ерғали Асқарбаев
Date : March 29 2020, 07:55 AM
To fix this issue Sorry, I misread the question.
You're going to need to consider several things. Yes, you need a buffer but you also have handle if your line is larger than your buffer. So you need two buffers, one to read into and another to assemble the whole line. While possible to do in one buffer it seemed overly complicated.
code :
#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>

int findchar(char*, int, char);

int main()
{
    size_t dataIn = open("myfile.txt", O_RDONLY);
    size_t gtOut = open("greaterthan.txt", O_CREAT | O_WRONLY);
    size_t coOut = open("colon.txt", O_CREAT | O_WRONLY);

    char buffer[12];
    int iReadCnt;
    char* lineBuffer = NULL;
    int lineBufferSize = 0;

    // read input file until no more input
    while (iReadCnt = read(dataIn, buffer, sizeof(buffer)))
    {
        int x;
        int n;
        char* b;

        // add buffer to dynamic line buffer
        n = lineBufferSize + iReadCnt;
        b = malloc(n);
        memcpy(b, lineBuffer, lineBufferSize);
        memcpy(&b[lineBufferSize], buffer, iReadCnt);
        // free old buffer if exists
        if (lineBuffer)
        {
            free(lineBuffer);
        }

        lineBufferSize = n;
        lineBuffer = b;

        // look for end of line
        x = findchar(lineBuffer, lineBufferSize, '\n');

        if (x >= 0)
        {
            int gtPos;
            int coPos;
            int n;
            char* b;

            // look for gt
            gtPos = findchar(lineBuffer, x, '>');

            if (gtPos >= 0)
            {
                write(gtOut, lineBuffer, x + 1);
            }

            // look for colon
            coPos = findchar(lineBuffer, x, ':');

            if (coPos >= 0)
            {
                write(coOut, lineBuffer, x + 1);
            }

            // remove line from buffer
            n = lineBufferSize - (x + 1);
            b = malloc(n);
            memcpy(b, &lineBuffer[x + 1], n);
            free(lineBuffer);
            lineBufferSize = n;
            lineBuffer = b;
        }
    }

    // close files
    close(dataIn);
    close(gtOut);
    close(coOut);
    exit(0);
}

// simple function to find a character in a buffer
int findchar(char* buffer, int len, char c)
{
    int i;
    for (i = 0; i < len; ++i)
    {
        if (buffer[i] == c)
        {
            return i;
        }
    }

    return -1;
}
Python dictionaries - find second character in a 2-character string which yields minimum value

Python dictionaries - find second character in a 2-character string which yields minimum value


By : BBoss
Date : March 29 2020, 07:55 AM
may help you . I would like to submit the first part of a key and return the remaining part of that key which minimizes the value (and starts with the first part).
code :
min(((d[s],s) for s in d if s.startswith('a')))[1][1:]
def smallest_value_of_key_startswith(a, d):
    min(((d[s],s) for s in d if s.startswith(a)))[1][len(a):]
Find character in string then insert character before that character

Find character in string then insert character before that character


By : Yassine Baassini
Date : March 29 2020, 07:55 AM
I think the issue was by ths following , Use strchr() (or strrchr()) to find the dot. Both functions have their prototype in .
There is no ready-made function for inserting a character in the middle of a string. You have to write your own.
How to find integer representing code point of special character? TypeError: ord() expected a character, but string of l

How to find integer representing code point of special character? TypeError: ord() expected a character, but string of l


By : Juan Andrey Valverde
Date : March 29 2020, 07:55 AM
Hope that helps I found classmethod int.from_bytes(bytes, byteorder, *, signed=False) which does the job instead of ord(). Code:
code :
characters = ['Č', 'č', 'Š', 'š', 'Ž', 'ž']
codecs = ['cp852', 'iso8859_2', 'cp1250', 'mac_latin2', 'utf-8', 'utf_16_le', 'utf_16_be']

for letter in characters:
    for codec in codecs:
        decCodePoint = int.from_bytes(letter.encode(codec), byteorder='big') #code point integer
        print(letter + ' ' + codec + ' ' + str(decCodePoint) + ' ' + str(hex(decCodePoint)) + ' ' + str(oct(decCodePoint))) #i also convert decimal integer to hexadecimal and octal
Č cp852 172 0xac 0o254
Č iso8859_2 200 0xc8 0o310
Č cp1250 200 0xc8 0o310
Č mac_latin2 137 0x89 0o211
Č utf-8 50316 0xc48c 0o142214
Č utf_16_le 3073 0xc01 0o6001
Č utf_16_be 268 0x10c 0o414
How did `find` actually locate a character in a string, when it was passed a string, not a character?

How did `find` actually locate a character in a string, when it was passed a string, not a character?


By : user2313347
Date : March 29 2020, 07:55 AM
seems to work fine Consult the official reference documentation. Functions in Red are highly polymorphic. find can either search for a given element or a first occurence of sub-series.
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