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Top Forums Programming String array iteration causing segfault Post 302850179 by bigearsbilly on Wednesday 4th of September 2013 05:52:43 AM
Old 09-04-2013
alternatively like so:

#include <stdio.h>
#include <string.h>

const char * names[] = {

int main(int argc, char* argv[])
    const char ** p;
    for( p = names; *p  ;p++)
            printf(" Name = %s    len = %d\n", *p, strlen(*p));

    return 0;


Last edited by bigearsbilly; 09-04-2013 at 06:57 AM.. Reason: const is better
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ENVZ_ADD(3)						     Library Functions Manual						       ENVZ_ADD(3)

envz_add, envz_entry, envz_get, envz_merge, envz_remove, envz_strip - environment string support SYNOPSIS
#include <envz.h> error_t envz_add(char **envz, size_t *envz_len, const char *name, const char *value); char * envz_entry(const char *envz, size_t *envz_len, const char *name); char * envz_get(const char *envz, size_t *envz_len, const char *name); error_t envz_merge(char **envz, size_t *envz_len, const char *envz2, size_t envz2_len, int override); void envz_remove(char **envz, size_t *envz_len, const char *name); void envz_strip(char **envz, size_t *envz_len); DESCRIPTION
These functions are glibc-specific. An argz vector is a pointer to a character buffer together with a length, see argz_add(3). An envz vector is a special argz vector, namely one where the strings have the form "name=value". Everything after the first '=' is considered to be the value. If there is no '=', the value is taken to be NULL. (While the value in case of a trailing '=' is the empty string "".) These functions are for handling envz vectors. envz_add() adds the string "name=value" (in case value is non-NULL) or "name" (in case value is NULL) to the envz vector (*envz,*envz_len) and updates *envz and *envz_len. If an entry with the same name existed, it is removed. envz_entry() looks for name in the envz vector (envz,envz_len) and returns the entry if found, or NULL if not. envz_get() looks for name in the envz vector (envz,envz_len) and returns the value if found, or NULL if not. (Note that the value can also be NULL, namely when there is an entry for name without '=' sign.) envz_merge() adds each entry in envz2 to *envz, as if with envz_add(). If override is true, then values in envz2 will supersede those with the same name in *envz, otherwise not. envz_remove() removes the entry for name from (*envz,*envz_len) if there was one. envz_strip removes all entries with value NULL. RETURN VALUE
All envz functions that do memory allocation have a return type of error_t, and return 0 for success, and ENOMEM if an allocation error occurs. EXAMPLE
#include <stdio.h> #include <envz.h> int main(int argc, char *argv[], char *envp[]) { int i, e_len = 0; char *str; for (i=0; envp[i] != NULL; i++) e_len += strlen(envp[i]) + 1; str = envz_entry(*envp, e_len, "HOME"); printf("%s ", str); str = envz_get(*envp, e_len, "HOME"); printf("%s ", str); return 0; } NOTES
These functions are a GNU extension. Handle with care. SEE ALSO
argz(3) ENVZ_ADD(3)

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