Calling curl command using byte buffer in Arduino












0














I'm currently working on Arduino devices and tying to use "process library" to call my REST API. Here's my code snippet.



void api_send_cell(uint8_t* data)
{
Process p;
p.begin("curl");
p.addParameter("-X Post");
p.addParameter("-H content-type: multipart/form-data");
p.addParameter("-k " + url);
p.addParameter("-F data=");
p.addParameter(buf);
p.run();
}


But the thing is that my data (uin8_t buffer) is a series of raw data which are just numbers from 0 to 255. Because the process needs string for parameter just like real command, I couldn't just put my data to addParamter function.



So, I think I have to convert those bytes to string representation (for example, hex string) somehow.



Is there any solution for this problem?










share|improve this question
























  • do you have a Yun board? this is not the way to do network communication in Atmega of Arduino Yun. use the Bridge library.
    – Juraj
    Nov 23 '18 at 9:01










  • You can improve your question by specifying the format of the string you need. Should the numbers be separated by spaces, commas, tabs, or something else?
    – jfowkes
    Nov 23 '18 at 12:08










  • @Juraj I'm using dragino LG01, and I thought it is ok to use process library because there are some example codes using that library.
    – goofcode
    Nov 23 '18 at 17:22
















0














I'm currently working on Arduino devices and tying to use "process library" to call my REST API. Here's my code snippet.



void api_send_cell(uint8_t* data)
{
Process p;
p.begin("curl");
p.addParameter("-X Post");
p.addParameter("-H content-type: multipart/form-data");
p.addParameter("-k " + url);
p.addParameter("-F data=");
p.addParameter(buf);
p.run();
}


But the thing is that my data (uin8_t buffer) is a series of raw data which are just numbers from 0 to 255. Because the process needs string for parameter just like real command, I couldn't just put my data to addParamter function.



So, I think I have to convert those bytes to string representation (for example, hex string) somehow.



Is there any solution for this problem?










share|improve this question
























  • do you have a Yun board? this is not the way to do network communication in Atmega of Arduino Yun. use the Bridge library.
    – Juraj
    Nov 23 '18 at 9:01










  • You can improve your question by specifying the format of the string you need. Should the numbers be separated by spaces, commas, tabs, or something else?
    – jfowkes
    Nov 23 '18 at 12:08










  • @Juraj I'm using dragino LG01, and I thought it is ok to use process library because there are some example codes using that library.
    – goofcode
    Nov 23 '18 at 17:22














0












0








0







I'm currently working on Arduino devices and tying to use "process library" to call my REST API. Here's my code snippet.



void api_send_cell(uint8_t* data)
{
Process p;
p.begin("curl");
p.addParameter("-X Post");
p.addParameter("-H content-type: multipart/form-data");
p.addParameter("-k " + url);
p.addParameter("-F data=");
p.addParameter(buf);
p.run();
}


But the thing is that my data (uin8_t buffer) is a series of raw data which are just numbers from 0 to 255. Because the process needs string for parameter just like real command, I couldn't just put my data to addParamter function.



So, I think I have to convert those bytes to string representation (for example, hex string) somehow.



Is there any solution for this problem?










share|improve this question















I'm currently working on Arduino devices and tying to use "process library" to call my REST API. Here's my code snippet.



void api_send_cell(uint8_t* data)
{
Process p;
p.begin("curl");
p.addParameter("-X Post");
p.addParameter("-H content-type: multipart/form-data");
p.addParameter("-k " + url);
p.addParameter("-F data=");
p.addParameter(buf);
p.run();
}


But the thing is that my data (uin8_t buffer) is a series of raw data which are just numbers from 0 to 255. Because the process needs string for parameter just like real command, I couldn't just put my data to addParamter function.



So, I think I have to convert those bytes to string representation (for example, hex string) somehow.



Is there any solution for this problem?







curl arduino arduino-yun






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 23 '18 at 17:12









gre_gor

4,06792631




4,06792631










asked Nov 23 '18 at 4:22









goofcode

105




105












  • do you have a Yun board? this is not the way to do network communication in Atmega of Arduino Yun. use the Bridge library.
    – Juraj
    Nov 23 '18 at 9:01










  • You can improve your question by specifying the format of the string you need. Should the numbers be separated by spaces, commas, tabs, or something else?
    – jfowkes
    Nov 23 '18 at 12:08










  • @Juraj I'm using dragino LG01, and I thought it is ok to use process library because there are some example codes using that library.
    – goofcode
    Nov 23 '18 at 17:22


















  • do you have a Yun board? this is not the way to do network communication in Atmega of Arduino Yun. use the Bridge library.
    – Juraj
    Nov 23 '18 at 9:01










  • You can improve your question by specifying the format of the string you need. Should the numbers be separated by spaces, commas, tabs, or something else?
    – jfowkes
    Nov 23 '18 at 12:08










  • @Juraj I'm using dragino LG01, and I thought it is ok to use process library because there are some example codes using that library.
    – goofcode
    Nov 23 '18 at 17:22
















do you have a Yun board? this is not the way to do network communication in Atmega of Arduino Yun. use the Bridge library.
– Juraj
Nov 23 '18 at 9:01




do you have a Yun board? this is not the way to do network communication in Atmega of Arduino Yun. use the Bridge library.
– Juraj
Nov 23 '18 at 9:01












You can improve your question by specifying the format of the string you need. Should the numbers be separated by spaces, commas, tabs, or something else?
– jfowkes
Nov 23 '18 at 12:08




You can improve your question by specifying the format of the string you need. Should the numbers be separated by spaces, commas, tabs, or something else?
– jfowkes
Nov 23 '18 at 12:08












@Juraj I'm using dragino LG01, and I thought it is ok to use process library because there are some example codes using that library.
– goofcode
Nov 23 '18 at 17:22




@Juraj I'm using dragino LG01, and I thought it is ok to use process library because there are some example codes using that library.
– goofcode
Nov 23 '18 at 17:22












1 Answer
1






active

oldest

votes


















0














You need to use sprintf to convert your uint8_t data to a string:



char string_data[LENGTH]; // LENGTH = Whatever length is sufficient to hold all your data
int i=0;
int index = 0;
//NUMBER_OF_ITEMS_OF_DATA could be constant or another variable
for (i=0; i<NUMBER_OF_ITEMS_OF_DATA; i++)
{
index += sprintf(&string_data[index], "%d,", data[i]);
}
p.addParameter(string_data);


This will convert an array like {1,2,3,4,5} into the string "1,2,3,4,5,".



You can change the "%d," in the sprintf call to get another format. You may also want to remove the trailing , depending on your requirements.






share|improve this answer





















  • Thank you for answering. Well, this is good enough. What i was trying to do was sending raw image data which uses a byte for a pixel. I was wondering if there is any way to send byte array itself, because it is lot easier to handle on server side and doesn't require any parsing process.
    – goofcode
    Nov 23 '18 at 17:28










  • Yeah, if you have zeros in your data you'll need to encode them somehow because HTTP is text-based and will interpret actual zero-bytes (0x00) as NULL. I'm not qualified to say what happens next, but it likely won't be what you intend.
    – jfowkes
    Nov 25 '18 at 22:09












  • Great, I decided to use hex because Arduino has String data type that gets byte and convert it to hex string. Thank you by the way.
    – goofcode
    Nov 26 '18 at 2:38













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1 Answer
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oldest

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1 Answer
1






active

oldest

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0














You need to use sprintf to convert your uint8_t data to a string:



char string_data[LENGTH]; // LENGTH = Whatever length is sufficient to hold all your data
int i=0;
int index = 0;
//NUMBER_OF_ITEMS_OF_DATA could be constant or another variable
for (i=0; i<NUMBER_OF_ITEMS_OF_DATA; i++)
{
index += sprintf(&string_data[index], "%d,", data[i]);
}
p.addParameter(string_data);


This will convert an array like {1,2,3,4,5} into the string "1,2,3,4,5,".



You can change the "%d," in the sprintf call to get another format. You may also want to remove the trailing , depending on your requirements.






share|improve this answer





















  • Thank you for answering. Well, this is good enough. What i was trying to do was sending raw image data which uses a byte for a pixel. I was wondering if there is any way to send byte array itself, because it is lot easier to handle on server side and doesn't require any parsing process.
    – goofcode
    Nov 23 '18 at 17:28










  • Yeah, if you have zeros in your data you'll need to encode them somehow because HTTP is text-based and will interpret actual zero-bytes (0x00) as NULL. I'm not qualified to say what happens next, but it likely won't be what you intend.
    – jfowkes
    Nov 25 '18 at 22:09












  • Great, I decided to use hex because Arduino has String data type that gets byte and convert it to hex string. Thank you by the way.
    – goofcode
    Nov 26 '18 at 2:38


















0














You need to use sprintf to convert your uint8_t data to a string:



char string_data[LENGTH]; // LENGTH = Whatever length is sufficient to hold all your data
int i=0;
int index = 0;
//NUMBER_OF_ITEMS_OF_DATA could be constant or another variable
for (i=0; i<NUMBER_OF_ITEMS_OF_DATA; i++)
{
index += sprintf(&string_data[index], "%d,", data[i]);
}
p.addParameter(string_data);


This will convert an array like {1,2,3,4,5} into the string "1,2,3,4,5,".



You can change the "%d," in the sprintf call to get another format. You may also want to remove the trailing , depending on your requirements.






share|improve this answer





















  • Thank you for answering. Well, this is good enough. What i was trying to do was sending raw image data which uses a byte for a pixel. I was wondering if there is any way to send byte array itself, because it is lot easier to handle on server side and doesn't require any parsing process.
    – goofcode
    Nov 23 '18 at 17:28










  • Yeah, if you have zeros in your data you'll need to encode them somehow because HTTP is text-based and will interpret actual zero-bytes (0x00) as NULL. I'm not qualified to say what happens next, but it likely won't be what you intend.
    – jfowkes
    Nov 25 '18 at 22:09












  • Great, I decided to use hex because Arduino has String data type that gets byte and convert it to hex string. Thank you by the way.
    – goofcode
    Nov 26 '18 at 2:38
















0












0








0






You need to use sprintf to convert your uint8_t data to a string:



char string_data[LENGTH]; // LENGTH = Whatever length is sufficient to hold all your data
int i=0;
int index = 0;
//NUMBER_OF_ITEMS_OF_DATA could be constant or another variable
for (i=0; i<NUMBER_OF_ITEMS_OF_DATA; i++)
{
index += sprintf(&string_data[index], "%d,", data[i]);
}
p.addParameter(string_data);


This will convert an array like {1,2,3,4,5} into the string "1,2,3,4,5,".



You can change the "%d," in the sprintf call to get another format. You may also want to remove the trailing , depending on your requirements.






share|improve this answer












You need to use sprintf to convert your uint8_t data to a string:



char string_data[LENGTH]; // LENGTH = Whatever length is sufficient to hold all your data
int i=0;
int index = 0;
//NUMBER_OF_ITEMS_OF_DATA could be constant or another variable
for (i=0; i<NUMBER_OF_ITEMS_OF_DATA; i++)
{
index += sprintf(&string_data[index], "%d,", data[i]);
}
p.addParameter(string_data);


This will convert an array like {1,2,3,4,5} into the string "1,2,3,4,5,".



You can change the "%d," in the sprintf call to get another format. You may also want to remove the trailing , depending on your requirements.







share|improve this answer












share|improve this answer



share|improve this answer










answered Nov 23 '18 at 12:04









jfowkes

754312




754312












  • Thank you for answering. Well, this is good enough. What i was trying to do was sending raw image data which uses a byte for a pixel. I was wondering if there is any way to send byte array itself, because it is lot easier to handle on server side and doesn't require any parsing process.
    – goofcode
    Nov 23 '18 at 17:28










  • Yeah, if you have zeros in your data you'll need to encode them somehow because HTTP is text-based and will interpret actual zero-bytes (0x00) as NULL. I'm not qualified to say what happens next, but it likely won't be what you intend.
    – jfowkes
    Nov 25 '18 at 22:09












  • Great, I decided to use hex because Arduino has String data type that gets byte and convert it to hex string. Thank you by the way.
    – goofcode
    Nov 26 '18 at 2:38




















  • Thank you for answering. Well, this is good enough. What i was trying to do was sending raw image data which uses a byte for a pixel. I was wondering if there is any way to send byte array itself, because it is lot easier to handle on server side and doesn't require any parsing process.
    – goofcode
    Nov 23 '18 at 17:28










  • Yeah, if you have zeros in your data you'll need to encode them somehow because HTTP is text-based and will interpret actual zero-bytes (0x00) as NULL. I'm not qualified to say what happens next, but it likely won't be what you intend.
    – jfowkes
    Nov 25 '18 at 22:09












  • Great, I decided to use hex because Arduino has String data type that gets byte and convert it to hex string. Thank you by the way.
    – goofcode
    Nov 26 '18 at 2:38


















Thank you for answering. Well, this is good enough. What i was trying to do was sending raw image data which uses a byte for a pixel. I was wondering if there is any way to send byte array itself, because it is lot easier to handle on server side and doesn't require any parsing process.
– goofcode
Nov 23 '18 at 17:28




Thank you for answering. Well, this is good enough. What i was trying to do was sending raw image data which uses a byte for a pixel. I was wondering if there is any way to send byte array itself, because it is lot easier to handle on server side and doesn't require any parsing process.
– goofcode
Nov 23 '18 at 17:28












Yeah, if you have zeros in your data you'll need to encode them somehow because HTTP is text-based and will interpret actual zero-bytes (0x00) as NULL. I'm not qualified to say what happens next, but it likely won't be what you intend.
– jfowkes
Nov 25 '18 at 22:09






Yeah, if you have zeros in your data you'll need to encode them somehow because HTTP is text-based and will interpret actual zero-bytes (0x00) as NULL. I'm not qualified to say what happens next, but it likely won't be what you intend.
– jfowkes
Nov 25 '18 at 22:09














Great, I decided to use hex because Arduino has String data type that gets byte and convert it to hex string. Thank you by the way.
– goofcode
Nov 26 '18 at 2:38






Great, I decided to use hex because Arduino has String data type that gets byte and convert it to hex string. Thank you by the way.
– goofcode
Nov 26 '18 at 2:38




















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