I am new to Linux OS and i am trying to compile a simpe c program
, I wrote it in using text editor
#include<stdio.h>
void main(){
printf("Hello!");
}
I typed gcc -o main main.c
and the following issue shows up
main.c:1:1: error: stray '\377' in program
# i n c l u d e < s t d i o . h >
main.c:1:2: error: stray '\376' in program
This happens whenever i run c or c++ program
\377 and \376 are an octal representation of the bytes that constitute the value 0xFEFF, the UTF-16 byte order marker. Your compiler doesn't expect those characters in your source code.
You need to change the encoding of your source file to either be UTF-8 or ASCII. Given the number of text editors that exist and the lack of that information in your question I cannot list every possibility for how to do that.
You could just do this in a bash shell:
cat > program.c
// File content here
^D
This will create a file called "program.c" with "// File content here" as its content, in UTF-8.
Your text editor is saving the program in the wrong character encoding. Save it as ASCII plain text and try again.
There is no text but encoded text.
With your editor, you have chosen to save your text file with the UTF-16LE character encoding (presumably).
Any program that reads a text file must know the character encoding of the text file. It could accept one documented character encoding (only or default) and/or allow you to tell it which you used.
This could work
gcc -finput-charset=UTF16-LE main.c
but since you have include files, the include files must use the same character encoding. On my system, they use UTF-8 (and include ©, which is good because gcc chokes on the bytes for that, letting me know that I've messed up).
Note: It's not very common to save a C source file (or most any text file) with UTF-16. UTF-8 is very common for all types of text files. (ASCII is also not very common, either. You might not find it as an option in many text editors. Historically, MS-DOS did not support it and Windows only got it very late and only for the sake of completeness.)
Related
I have a problem compiling the following exploit code:
http://downloads.securityfocus.com/vulnerabilities/exploits/59846-1.c
I am using "gcc file.c" and "gcc -O2 file.c", but both of them results in the following errors:
sorbolinux-exec.c: In function ‘sc’:
sorbolinux-exec.c:76: error: stray ‘\302’ in program
sorbolinux-exec.c:76: error: stray ‘\244’ in program
sorbolinux-exec.c:76: error: ‘t’ undeclared (first use in this function)
sorbolinux-exec.c:76: error: (Each undeclared identifier is reported only once
sorbolinux-exec.c:76: error: for each function it appears in.)
I tried compiling them on both Kali Linux and Ubuntu 10.04 (Lucid Lynx) and got the same result.
You have an invalid character on that line. This is what I saw:
You have invalid characters in your source. If you don't have any valid non-ASCII characters in your source, maybe in a double quoted string literal, you can simply convert your file back to ASCII with:
tr -cd '\11\12\15\40-\176' < old.c > new.c
The method with iconv will stop at wrong characters which makes no sense. The above command line is working with the example file.
Sure, convert the file to ASCII and blast all Unicode characters away.
It will probably work... But...
You won't know what you fixed.
It will also destroy any Unicode comments. Example: //: A²+B²=C²
It could potentially damage obvious logic and the code will still be broken,
but the solution less obvious.
For example: A string with "Smart-Quotes" (“ & ”) or a pointer with a full-width asterisk (＊). Now “SOME_THING” looks like a #define (SOME_THING) and ＊SomeType is the wrong type (SomeType).
Two more surgical approaches to fixing the problem:
Switch fonts to see the character. (It might be invisible in your current font)
Regular expression search all Unicode characters not part of non-extended ASCII.
In Notepad++ I can search up to FFFF, which hasn't failed me yet.
[\x{80}-\x{FFFF}]
80 is hex for 128, the first extended ASCII character.
After hitting "find next" and highlighting what appears to be empty space, you can close your search dialog and press Ctrl + C to copy to clipboard.
Then paste the character into a Unicode search tool.
I usually use an online one.
http://unicode.scarfboy.com/
Example:
I had a bullet point (•) in my code somehow.
The Unicode value is 2022 (hex), but when read as ASCII by the compiler
you get \342 \200 \242 (3 octal values). It's not as simple as converting each octal values to hex and smashing them together. So "E2 80 A2" is not the hexadecimal Unicode point in your code.
I got the same with a character that visibly appeared as an asterisk, but it was a UTF-8 sequence instead:
Encoder * st;
When compiled, it returned:
g.c:2:1: error: stray ‘\342’ in program
g.c:2:1: error: stray ‘\210’ in program
g.c:2:1: error: stray ‘\227’ in program
342 210 227 turns out to be UTF-8 for ASTERISK OPERATOR (Unicode code point U+2217).
Deleting the '*' and typing it again fixed the problem.
Whenever the compiler found a special character, it gives these kind of compile errors. The error I found is as follows:
error: stray '\302' in program and error: stray '\240' in program
....
It is some piece of code I copied from a chat messenger. In Facebook Messenger, it was a special character only. After copying into the Vim editor it changed to the correct character only. But the compiler was giving the above error .. then .. that statement I wrote manually after .. it got resolved... :)
It's perhaps because you copied code from the Internet (from a site which has perhaps not an ASCII encoded page, but a UTF-8 encoded page), so you can convert the code to ASCII from this site:
"http://www.percederberg.net/tools/text_converter.html"
There you can either detect errors manually by converting it back to UTF-8, or you can automatically convert it to ASCII and remove all the stray characters.
This problem comes when you have copied some text from an HTML page or you have done modification in a Windows environment and are trying to compile in a Unix/Solaris environment.
Please do "dos2unix" to remove the special characters from the file:
dos2unix fileName.ext fileName.ext
Invalid character in your code.
It is a common copy-paste error, especially when code is copied from Microsoft Word documents or PDF files.
I noticed an issue in using the above tr command. The tr command COMPLETELY removes the "smart quotes". It would be better to replace the "smart quotes" with something like this.
This will give you a quick preview of what will be replaced.
sed s/[”“]/'"'/g File.txt
This will do the replacements and put the replacement in a new file called WithoutSmartQuotes.txt.
sed s/[”“]/'"'/g File.txt > WithoutSmartQuotes.txt
This will overwrite the original file.
sed -i ".bk" s/[”“]/'"'/g File.txt
http://developmentality.wordpress.com/2010/10/11/how-to-remove-smart-quotes-from-a-text-file/
Codo was exactly right on Oct. 5 that ¤t[i] is the intended text (with the currency symbol inadvertently introduced when the source was put into HTML (see original):
http://downloads.securityfocus.com/vulnerabilities/exploits/59846-1.c
Codo's change makes this exploit code compile without error. I did that and was able to use the exploit on Ubuntu 12.04 (Precise Pangolin) to escalate to root privilege.
The explanations given here are correct. I just wanted to add that this problem might be because you copied the code from somewhere, from a website or a PDF file due to which there are some invalid characters in the code.
Try to find those invalid characters, or just retype the code if you can't. It will definitely compile then.
Source: stray error reason
With me, this error occurred when I copied and pasted code in text format to my editor (gedit).
The code was in a text document (.odt). I copied it and pasted it into gedit.
If you did the same, you have manually rewrite the code.
I have a problem compiling the following exploit code:
http://downloads.securityfocus.com/vulnerabilities/exploits/59846-1.c
I am using "gcc file.c" and "gcc -O2 file.c", but both of them results in the following errors:
sorbolinux-exec.c: In function ‘sc’:
sorbolinux-exec.c:76: error: stray ‘\302’ in program
sorbolinux-exec.c:76: error: stray ‘\244’ in program
sorbolinux-exec.c:76: error: ‘t’ undeclared (first use in this function)
sorbolinux-exec.c:76: error: (Each undeclared identifier is reported only once
sorbolinux-exec.c:76: error: for each function it appears in.)
I tried compiling them on both Kali Linux and Ubuntu 10.04 (Lucid Lynx) and got the same result.
You have an invalid character on that line. This is what I saw:
You have invalid characters in your source. If you don't have any valid non-ASCII characters in your source, maybe in a double quoted string literal, you can simply convert your file back to ASCII with:
tr -cd '\11\12\15\40-\176' < old.c > new.c
The method with iconv will stop at wrong characters which makes no sense. The above command line is working with the example file.
Sure, convert the file to ASCII and blast all Unicode characters away.
It will probably work... But...
You won't know what you fixed.
It will also destroy any Unicode comments. Example: //: A²+B²=C²
It could potentially damage obvious logic and the code will still be broken,
but the solution less obvious.
For example: A string with "Smart-Quotes" (“ & ”) or a pointer with a full-width asterisk (＊). Now “SOME_THING” looks like a #define (SOME_THING) and ＊SomeType is the wrong type (SomeType).
Two more surgical approaches to fixing the problem:
Switch fonts to see the character. (It might be invisible in your current font)
Regular expression search all Unicode characters not part of non-extended ASCII.
In Notepad++ I can search up to FFFF, which hasn't failed me yet.
[\x{80}-\x{FFFF}]
80 is hex for 128, the first extended ASCII character.
After hitting "find next" and highlighting what appears to be empty space, you can close your search dialog and press Ctrl + C to copy to clipboard.
Then paste the character into a Unicode search tool.
I usually use an online one.
http://unicode.scarfboy.com/
Example:
I had a bullet point (•) in my code somehow.
The Unicode value is 2022 (hex), but when read as ASCII by the compiler
you get \342 \200 \242 (3 octal values). It's not as simple as converting each octal values to hex and smashing them together. So "E2 80 A2" is not the hexadecimal Unicode point in your code.
I got the same with a character that visibly appeared as an asterisk, but it was a UTF-8 sequence instead:
Encoder * st;
When compiled, it returned:
g.c:2:1: error: stray ‘\342’ in program
g.c:2:1: error: stray ‘\210’ in program
g.c:2:1: error: stray ‘\227’ in program
342 210 227 turns out to be UTF-8 for ASTERISK OPERATOR (Unicode code point U+2217).
Deleting the '*' and typing it again fixed the problem.
Whenever the compiler found a special character, it gives these kind of compile errors. The error I found is as follows:
error: stray '\302' in program and error: stray '\240' in program
....
It is some piece of code I copied from a chat messenger. In Facebook Messenger, it was a special character only. After copying into the Vim editor it changed to the correct character only. But the compiler was giving the above error .. then .. that statement I wrote manually after .. it got resolved... :)
It's perhaps because you copied code from the Internet (from a site which has perhaps not an ASCII encoded page, but a UTF-8 encoded page), so you can convert the code to ASCII from this site:
"http://www.percederberg.net/tools/text_converter.html"
There you can either detect errors manually by converting it back to UTF-8, or you can automatically convert it to ASCII and remove all the stray characters.
This problem comes when you have copied some text from an HTML page or you have done modification in a Windows environment and are trying to compile in a Unix/Solaris environment.
Please do "dos2unix" to remove the special characters from the file:
dos2unix fileName.ext fileName.ext
Invalid character in your code.
It is a common copy-paste error, especially when code is copied from Microsoft Word documents or PDF files.
I noticed an issue in using the above tr command. The tr command COMPLETELY removes the "smart quotes". It would be better to replace the "smart quotes" with something like this.
This will give you a quick preview of what will be replaced.
sed s/[”“]/'"'/g File.txt
This will do the replacements and put the replacement in a new file called WithoutSmartQuotes.txt.
sed s/[”“]/'"'/g File.txt > WithoutSmartQuotes.txt
This will overwrite the original file.
sed -i ".bk" s/[”“]/'"'/g File.txt
http://developmentality.wordpress.com/2010/10/11/how-to-remove-smart-quotes-from-a-text-file/
Codo was exactly right on Oct. 5 that ¤t[i] is the intended text (with the currency symbol inadvertently introduced when the source was put into HTML (see original):
http://downloads.securityfocus.com/vulnerabilities/exploits/59846-1.c
Codo's change makes this exploit code compile without error. I did that and was able to use the exploit on Ubuntu 12.04 (Precise Pangolin) to escalate to root privilege.
The explanations given here are correct. I just wanted to add that this problem might be because you copied the code from somewhere, from a website or a PDF file due to which there are some invalid characters in the code.
Try to find those invalid characters, or just retype the code if you can't. It will definitely compile then.
Source: stray error reason
With me, this error occurred when I copied and pasted code in text format to my editor (gedit).
The code was in a text document (.odt). I copied it and pasted it into gedit.
If you did the same, you have manually rewrite the code.
I'm new to C and I came across this code and it was confusing me:
sprintf(banner1, "\e[37╔═╗\e[37┌─┐\e[37┌┐┌\e[37┌─┐\e[37┌─┐\e[37┌─┐\e[37┌─┐\e[37m\r\n");
sprintf(banner2, "\e[37╠═╝\e[37├─┤\e[37│││\e[37│ ┬\e[37├─┤\e[37├┤\e[37 ├─┤\e[37m\r\n");
sprintf(banner3, "\e[37╩ \e[37┴ ┴┘\e[37└┘\e[37└─┘\e[37┴ ┴\e[37└─┘\e[37┴ ┴\e[37m\r\n");
I was just confused as I don't know what do \e[37 and \r\n mean. And can I change the colors?
This looks like an attempt to use ANSI terminal color escapes and Unicode box drawing characters to write the word "PANGAEA" in a large, stylized, colorful manner. I'm guessing it's part of a retro-style BBS or MUD system, intended to be interacted with over telnet or ssh. It doesn't work, because whoever wrote it made a bunch of mistakes. Here's a corrected, self-contained program:
#include <stdio.h>
int main(void)
{
printf("\e[31m╔═╗\e[32m┌─┐ \e[33m┌┐┌\e[34m┌─┐\e[35m┌─┐\e[36m┌─┐\e[37m┌─┐\e[0m\n");
printf("\e[31m╠═╝\e[32m├─┤ \e[33m│││\e[34m│ ┬\e[35m├─┤\e[36m├┤ \e[37m├─┤\e[0m\n");
printf("\e[31m╩ \e[32m┴ ┴┘\e[33m┘└┘\e[34m└─┘\e[35m┴ ┴\e[36m└─┘\e[37m┴ ┴\e[0m\n");
return 0;
}
The mistakes were: using \r\n instead of plain \n, leaving out the m at the end of each and every escape sequence, and a number of typos in the actual letters (missing spaces and the like).
I deliberately changed sprintf(bannerN, ... to printf to make it a self-contained program instead of a fragment of a larger system, and changed the actual color codes used for each letter to make it a more interesting demo. When I run this program on my computer I get this output:
The program will only work on your computer if your terminal emulator supports both ANSI color escapes and printing UTF-8 with no special ceremony. Most Unix-style operating systems nowadays support both by default; I don't know about Windows.
I have a problem compiling the following exploit code:
http://downloads.securityfocus.com/vulnerabilities/exploits/59846-1.c
I am using "gcc file.c" and "gcc -O2 file.c", but both of them results in the following errors:
sorbolinux-exec.c: In function ‘sc’:
sorbolinux-exec.c:76: error: stray ‘\302’ in program
sorbolinux-exec.c:76: error: stray ‘\244’ in program
sorbolinux-exec.c:76: error: ‘t’ undeclared (first use in this function)
sorbolinux-exec.c:76: error: (Each undeclared identifier is reported only once
sorbolinux-exec.c:76: error: for each function it appears in.)
I tried compiling them on both Kali Linux and Ubuntu 10.04 (Lucid Lynx) and got the same result.
You have an invalid character on that line. This is what I saw:
You have invalid characters in your source. If you don't have any valid non-ASCII characters in your source, maybe in a double quoted string literal, you can simply convert your file back to ASCII with:
tr -cd '\11\12\15\40-\176' < old.c > new.c
The method with iconv will stop at wrong characters which makes no sense. The above command line is working with the example file.
Sure, convert the file to ASCII and blast all Unicode characters away.
It will probably work... But...
You won't know what you fixed.
It will also destroy any Unicode comments. Example: //: A²+B²=C²
It could potentially damage obvious logic and the code will still be broken,
but the solution less obvious.
For example: A string with "Smart-Quotes" (“ & ”) or a pointer with a full-width asterisk (＊). Now “SOME_THING” looks like a #define (SOME_THING) and ＊SomeType is the wrong type (SomeType).
Two more surgical approaches to fixing the problem:
Switch fonts to see the character. (It might be invisible in your current font)
Regular expression search all Unicode characters not part of non-extended ASCII.
In Notepad++ I can search up to FFFF, which hasn't failed me yet.
[\x{80}-\x{FFFF}]
80 is hex for 128, the first extended ASCII character.
After hitting "find next" and highlighting what appears to be empty space, you can close your search dialog and press Ctrl + C to copy to clipboard.
Then paste the character into a Unicode search tool.
I usually use an online one.
http://unicode.scarfboy.com/
Example:
I had a bullet point (•) in my code somehow.
The Unicode value is 2022 (hex), but when read as ASCII by the compiler
you get \342 \200 \242 (3 octal values). It's not as simple as converting each octal values to hex and smashing them together. So "E2 80 A2" is not the hexadecimal Unicode point in your code.
I got the same with a character that visibly appeared as an asterisk, but it was a UTF-8 sequence instead:
Encoder * st;
When compiled, it returned:
g.c:2:1: error: stray ‘\342’ in program
g.c:2:1: error: stray ‘\210’ in program
g.c:2:1: error: stray ‘\227’ in program
342 210 227 turns out to be UTF-8 for ASTERISK OPERATOR (Unicode code point U+2217).
Deleting the '*' and typing it again fixed the problem.
Whenever the compiler found a special character, it gives these kind of compile errors. The error I found is as follows:
error: stray '\302' in program and error: stray '\240' in program
....
It is some piece of code I copied from a chat messenger. In Facebook Messenger, it was a special character only. After copying into the Vim editor it changed to the correct character only. But the compiler was giving the above error .. then .. that statement I wrote manually after .. it got resolved... :)
It's perhaps because you copied code from the Internet (from a site which has perhaps not an ASCII encoded page, but a UTF-8 encoded page), so you can convert the code to ASCII from this site:
"http://www.percederberg.net/tools/text_converter.html"
There you can either detect errors manually by converting it back to UTF-8, or you can automatically convert it to ASCII and remove all the stray characters.
This problem comes when you have copied some text from an HTML page or you have done modification in a Windows environment and are trying to compile in a Unix/Solaris environment.
Please do "dos2unix" to remove the special characters from the file:
dos2unix fileName.ext fileName.ext
Invalid character in your code.
It is a common copy-paste error, especially when code is copied from Microsoft Word documents or PDF files.
I noticed an issue in using the above tr command. The tr command COMPLETELY removes the "smart quotes". It would be better to replace the "smart quotes" with something like this.
This will give you a quick preview of what will be replaced.
sed s/[”“]/'"'/g File.txt
This will do the replacements and put the replacement in a new file called WithoutSmartQuotes.txt.
sed s/[”“]/'"'/g File.txt > WithoutSmartQuotes.txt
This will overwrite the original file.
sed -i ".bk" s/[”“]/'"'/g File.txt
http://developmentality.wordpress.com/2010/10/11/how-to-remove-smart-quotes-from-a-text-file/
Codo was exactly right on Oct. 5 that ¤t[i] is the intended text (with the currency symbol inadvertently introduced when the source was put into HTML (see original):
http://downloads.securityfocus.com/vulnerabilities/exploits/59846-1.c
Codo's change makes this exploit code compile without error. I did that and was able to use the exploit on Ubuntu 12.04 (Precise Pangolin) to escalate to root privilege.
The explanations given here are correct. I just wanted to add that this problem might be because you copied the code from somewhere, from a website or a PDF file due to which there are some invalid characters in the code.
Try to find those invalid characters, or just retype the code if you can't. It will definitely compile then.
Source: stray error reason
With me, this error occurred when I copied and pasted code in text format to my editor (gedit).
The code was in a text document (.odt). I copied it and pasted it into gedit.
If you did the same, you have manually rewrite the code.
New to the community, but not new to programming.
I've been trying to get a collection of hash functions up/running and I succeeded. However I found some weird results and haven't been able to put my finger on it yet. RFC4634 contains a C implementation for SHA-1 and SHA-2 family, which also can accept a file being passed on for hashing. RFC3174 contains a C implementation, but doesn't process file streams. I've been using the C implementation from RFC4634 to verify files, yet the verification process is returning non similar results when I compare them against SHA-1 provided hashes.
Any idea what the reasons could be?
Did you check if you opened the files in ASCII or binary mode? Line end translation may be performed before the hash is being calculated.
Update:
I just compiled the RFC4634 shatestand tried on a sample text file. As long as there isn't a line break, all tools agree. Once you insert a line break, results depend: if the text file uses CR and LF (DOS mode), then shatest produces a different result. If the line end is only LF (UNIX), it still agrees with the other tools.
Update 2:
In the file shatest.c of RFC4634, in function hashfile(...), set fopen to binary mode:
FILE *hashfp = (strcmp(hashfilename, "-") == 0) ? stdin :
fopen(hashfilename, "rb");
/* ^ HERE */