How to convert uppercase letters to lowercase in C language

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#! / bin/bash

# name: upper_to_lower.sh

# the function is trun uper to lower

# like ABCd to abcd

Haveuppernumber ()

{

# test if the string have upper number

Str= "$(echo $1 | tr'[: upper:]'[: lower:]')"

If ["$str"! = $1]; then # get some problem

Echo "[# have upper number,and i well trun them to lower:#]"

Return 1 # have upper number

Else

Return 0 # no upper number

Fi

}

If [$#-ne 1]; then

Echo "Usage: $0" > & 2

Exit 1

Fi

If! Haveuppernumber $1; then # when if is 0 it run?

# if [0]; then # in shell true return 0, false return 1

Echo $1 | tr'[: upper:]'[: lower:]'# it can turn the UPPER number to lower

# echo $1 | tr'[: lower:]'[: upper:]'# it can turn the lower number to UPPER

Else

Echo "[# no upper number:#]"

Echo $1

Fi

Exit 0

Function description: when entering ". / upper_to_lower.sh AaBbCcdd" will first determine whether the input format is correct, and then determine whether there are uppercase letters in the string if there is a display of "[# have upper number,and i well trun them to lower:#]" and the string converted to lowercase letters; if there are no uppercase letters display "[# no upper number:#]" and lowercase string.

Then try to achieve the same function in C language, as follows:

The code is as follows:

# include

# include

Int haveuppernumber (char * p)

{

Char*q=p

For (; * QQ stories'\ 0percent investors +)

{

If (* Q > = 'Asians, girls, boys, girls, boys, girls, girls, boys, girls,