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Full Discussion: question about popen in C
Top Forums Programming question about popen in C Post 302504984 by omega666 on Tuesday 15th of March 2011 10:51:11 PM
Old 03-15-2011
i made a function similar to peopen, how can i test if it works?
Code:
    FILE *file_pointer; char output[512];
    file_pointer = popen_new(COMMAND, "r");
    size_t bytes = read(fileno(file_pointer), output, 512); 
    printf(output);
    pclose_new(file_pointer);

this gave me the expected output
Code:
    file_pointer = popen_new(TEST_COMMAND, "w");
    write(fileno(file_pointer), output, bytes); 
    pclose_new(file_pointer);

this one i also get expected results, but i am still not sure if its right, the output was the result of the COMMAND string, but what can i do after writing to see if it worked, i cant read it since its in write mode...
 

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STRCSTR(3pub)						       C Programmer's Manual						     STRCSTR(3pub)

NAME
strcstr - convert memory block to printable C string notation SYNOPSIS
#include <publib.h> void strcstr(char *str, size_t max, const void *block, size_t n); DESCRIPTION
strcstr converts the contents of an arbitrary memory block (which need not be a zero terminated string) into a printable notation using normal C string literal syntax. This can be used for example to store potentially binary data in a file, or in debugging outputs. All characters for which there is a simple shorthand escape sequence (', ", ?, , a, , f, , , , v) are stored using that nota- tion. is stored as . All other non-printable characters are stored using a hexadecimal escape sequence. All other printable charac- ters are stored as is. The isprint(3) macro is used to determine whether a character is printable (i.e., whether it is printed as is, or using special notation). Therefore, the output depends on the locale. RETURN VALUE
strcstr returns nothing. EXAMPLE
The following code dumps input to the standard output in a guaranteed (modulo locale bugs) printable format. It might be used for debug- ging. #include <stdio.h> #include <publib.h> int main(void) { char line[512]; char cstr[512*(CHAR_BIT/4+1+2)+1]; /* +2 for x, +1 for , the rest to be able to store the hex code for 512 chars. */ while (fgets(line, sizeof(line), stdin) != NULL) { strcstr(cstr, sizeof(cstr), line, strlen(line)); printf("%s0, cstr); } return 0; } SEE ALSO
publib(3), strins(3) AUTHOR
Lars Wirzenius (lars.wirzenius@helsinki.fi) Publib C Programmer's Manual STRCSTR(3pub)
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